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Sight is anything that is seen with the Eyes. Catch sight of; to perceive with the eyes. The ability to see; the visual faculty. The range of vision. The act of looking or seeing or observing.

Spatial Intelligence - Light

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40 million people in the world are Blind, around one in every 200 people on Earth. Another 246 million have low vision to degrees that impose moderate or severe limits. Vision loss also affects hundreds of millions more people. Often relatives, devoted to aiding those who can’t see. Many become blind after many years of slow and progressive retinal degeneration.

Blind - Sight Problems

Eyes of a Baby Close UpSEE International provides sustainable medical, surgical, and educational services through volunteer ophthalmic surgeons with the objectives of restoring sight and preventing blindness to disadvantaged individuals worldwide.

American Foundation for the Blind

Blindness is a decreased ability to see to a degree that causes problems not fixable by usual means, such as glasses. Some also include those who have a decreased ability to see because they do not have access to glasses or contact lenses. Visual impairment is often defined as a best corrected visual acuity of worse than either 20/40 or 20/60. The term blindness is used for complete or nearly complete vision loss. Visual impairment may cause people difficulties with normal daily activities such as driving, reading, socializing, and walking.

Myopia or Near-sightedness is a condition of the eye where light focuses in front of, instead of on, the retina. This causes distant objects to be blurry while close objects appear normal. Other symptoms may include headaches and eye strain. Severe near-sightedness increases the risk of retinal detachment, cataracts, and glaucoma.

Cataract is a clouding of the lens in the eye which leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colors, blurry vision, halos around light, trouble with bright lights, and trouble seeing at night.

Cataract Diagnosis and Treatment using LED technology to measure cataracts at a molecular level.

The Gift of Sight is working to eliminate preventable and curable blindness throughout the developing world. Himalayan Cataract Project.

Blurring is to make less clear and become vague or not clearly defined or easy to perceive or understand.

Farsighted children struggle with Attention.

Glaucoma is a group of eye diseases which result in damage to the optic nerve and vision loss. The most common type is open-angle glaucoma with less common types including closed-angle glaucoma and normal-tension glaucoma. Open-angle glaucoma develops slowly over time and there is no pain. Side vision may begin to decrease followed by central vision resulting in blindness if not treated. Closed-angle glaucoma can present gradually or suddenly. The sudden presentation may involve severe eye pain, blurred vision, mid-dilated pupil, redness of the eye, and nausea. Vision loss from glaucoma, once it has occurred, is permanent.

Macular Degeneration is a medical condition which may result in blurred or no vision in the center of the visual field. Early on there are often no symptoms. Over time, however, some people experience a gradual worsening of vision that may affect one or both eyes. While it does not result in complete blindness, loss of central vision can make it hard to recognize faces, drive, read, or perform other activities of daily life. Visual hallucinations may also occur but these do not represent a mental illness.

Blindsight is the ability of people who are cortically blind due to lesions in their striate cortex, also known as primary visual cortex or V1, to respond to visual stimuli that they do not consciously see.

Cortical Blindness is the total or partial loss of vision in a normal-appearing eye caused by damage to the brain's occipital cortex. Cortical blindness can be acquired or congenital, and may also be transient in certain instances.

Ophthalmic Pathology deals with the diagnosis and characterization of neoplastic and non-neoplastic diseases of the eyes. Ophthalmic pathologists generally work closely with ophthalmologists.
The Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW)

Strabismus is a condition in which the eyes do not properly align with each other when looking at an object. Which eye is focused on the object in question can switch. It may also be present occasionally or constantly. If present during a large part of childhood, it may result in amblyopia or loss of depth perception. Adults may have double vision.

Esotropia is a form of strabismus in which one or both eyes turns inward. The condition can be constantly present, or occur intermittently, and can give the affected individual a "cross-eyed" appearance. It is the opposite of Exotropia. Esotropia is sometimes erroneously called "lazy eye", which describes the condition of amblyopia—a reduction in vision of one or both eyes that is not the result of any pathology of the eye and cannot be resolved by the use of corrective lenses. Amblyopia can, however, arise as a result of esotropia occurring in childhood: In order to relieve symptoms of diplopia or double vision, the child's brain will ignore or "suppress" the image from the esotropic eye, which when allowed to continue untreated will lead to the development of amblyopia. Treatment options for esotropia include glasses to correct refractive errors (see accommodative esotropia below), the use of prisms and/or orthoptic exercises and/or eye muscle surgery. The term is from Greek eso meaning "inward" and trope meaning "a turning".

Dark Adaptation Threshold is a vision test that measures the adjustment of the eye occurring under low levels of illumination. When light enters the eye, it ultimately reaches the rods and cones, which are two types of cells in the retina. Rods handle vision in low light conditions and cones handle color vision and detail. The rods and cones each react differently during the DAT test, and are measured on a graph. The test determines the threshold, or minimum light intensity required to produce a visual sensation in the child's eye. In order to perform this test, the child is asked to sit in the dark for a half-hour. This allows the eyes to be most sensitive for the test. Once the eyes have fully adapted, the child stands in front of a black projection screen. Dim spots of light are projected onto the screen, one at a time, on either the right or the left side. The spots get dimmer as the test goes on. The child is asked to point to the spots until he or she can no longer distinguish them. In order to keep the child's attention on the screen, sometimes the doctor will wave a brighter light on the screen to hold the child's interest when the test becomes harder to see. When an infant is being tested, an observer with a night vision camera records the head and eye movements of the child as they look at the spots. Once the patient can no longer see the spots, the dark adapted threshold is determined. The DAT test lasts for about 10 to 15 minutes.

Testing Sight - Eye Exams

Eye Chart (image)

Green Eyes of a Women Close Up Stand 20 feet from the Chart at eye level (cover one eye but don't close the eye or press on the eye).

20/20 vision means that the test subject sees the same line of letters at 20 feet that person with normal vision sees at 20 feet. 20/40 vision means that the test subject sees at 20 feet what a person with normal vision sees at 40 feet.
20/40 - Able to pass Driver's License Test in all 50 States. Most printed material is at this level.
20/80 - Able to read alarm clock at 10 feet. News Headlines are this size.
20/200 - Legal blindness. Able to see STOP sign letters.

2020 Vision numerator ( the top or first number 20 ) refers to a distance and the Demoninator refers to a size. Since the standard distance of the chart is 20 feet which is equivalent to 6 meters the term 2020 Vision or Vision 2020 refers to the ability to see a certain size letter at a certain distance from the eye. In this case size a size 20 Letter at 20 feet. The term ""6/6 vision"" is used as the meter equivalent.

Eyesight Check
Eye Test Game
Eye Health - Eye Exams 101
Eye Exam Seeing Test

Smartphone Apps for Measuring Eyesight

20 20 20 Rule is every 20 minutes, stare and focus at an object 20 feet or more away for 20 seconds. This helps reduce eyestrain.

Improve Vision Naturally
Improve Eyesight (youtube)
Glasses Off App
How to See Without Glasses
ZEISS Vision Care

Eyeglass Prescription
OD = Right Eye
OS = Left Eye
DV is your prescription which corrects your ability to see things far away (distance vision).
NV means your prescription is for reading only (near vision).

Visual Acuity refers to the clarity of vision. Visual acuity is dependent on optical and neural factors, i.e., (i) the sharpness of the retinal focus within the eye, (ii) the health and functioning of the retina, and (iii) the sensitivity of the interpretative faculty of the brain. A common cause of low visual acuity is refractive error (ametropia), or errors in how the light is refracted in the eyeball. Causes of refractive errors include aberrations in the shape of the eyeball, the shape of the cornea, and reduced flexibility of the lens. Too high or too low refractive error (in relation to the length of the eyeball) is the cause of nearsightedness (myopia) or farsightedness (hyperopia) (normal refractive status is referred to as emmetropia). Other optical causes are astigmatism or more complex corneal irregularities. These anomalies can mostly be corrected by optical means (such as eyeglasses, contact lenses, laser surgery, etc.).

Andrew Bastawrous: Get your next eye exam on a Smartphone (Video)
Peek Vision

Eyeque Personal Vision Tracker is the affordable way to test your vision using your smartphone.

White Eye Detector App

Visual Field Test is an eye examination that can detect dysfunction in central and peripheral vision which may be caused by various medical conditions such as glaucoma, stroke, pituitary disease, brain tumours or other neurological deficits. Visual field testing can be performed clinically by keeping the subject's gaze fixed while presenting objects at various places within their visual field. Simple manual equipment can be used such as in the tangent screen test or the Amsler grid. When dedicated machinery is used it is called a perimeter.

Visual Fields easy Eye Exam App capture high-quality images of the front and back of an eye.

Spatial Intelligence (visual perception) - Awareness - Mind Maps

eye anatomy Human Eyes is an organ which reacts to light and pressure. As a sense organ, the mammalian eye allows vision. Human eyes help provide a three dimensional, moving image, normally coloured in daylight. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth. The human eye can distinguish about 10 million colors and is possibly capable of detecting a single photon.

How Human Eye Works
Anatomy of the Eye

Eye are organs of the Visual System. They provide organisms vision, the ability to process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and convert it into electro-chemical impulses in neurons.

Optometry is a health care profession which involves examining the eyes and applicable visual systems for defects or abnormalities as well as the medical diagnosis and management of eye disease.

Ophthalmology is the branch of medicine that deals with the anatomy, physiology and diseases of the eyeball and orbit. An ophthalmologist is a specialist in medical and surgical eye problems. Their credentials include an M.D. or D.O. degree, and an additional four years of residency. Ophthalmologists are allowed to medically treat eye disease, implement laser therapy, and perform incisional surgery when warranted.

International Council of Ophthalmology
A. Academy of Ophthalmology
Review of Ophthalmology
American Optometric Association
Association for Research in Vision and Ophthalmology branch of medicine concerned with the eye and its diseases.
Wills Eye Hospital
National Institutes of Health

Visual Cortex (Brain)

Lateral Geniculate Nucleus is a relay center in the thalamus for the visual pathway. It receives a major sensory input from the retina. The LGN is the main central connection for the optic nerve to the occipital lobe. In humans, each LGN has six layers of neurons (grey matter) alternating with optic fibers (white matter).

Retina is the third and inner coat of the eye which is a light-sensitive layer of tissue. The optics of the eye create an image of the visual world on the retina (through the cornea and lens), which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical events that ultimately trigger nerve impulses. These are sent to various visual centres of the brain through the fibres of the optic nerve. Neural retina typically refers to three layers of neural cells (photo receptor cells, bipolar cells, and ganglion cells) within the retina, while the entire retina refers to these three layers plus a layer of pigmented epithelial cells. The retina sits at the back of the human eye, and contains protein cells that convert light into electrical signals that travel through the nervous system, triggering a response from the brain, ultimately building a picture of the scene being viewed. Just as photography depends on camera pixels reacting to light, vision relies on the retina performing the same function.

Optic Nerve is a paired nerve that transmits visual information from the retina to the brain. The optic nerve is derived from optic stalks during the seventh week of development and is composed of retinal ganglion cell axons and glial cells. In humans, the optic nerve extends from the optic disc to the optic chiasm and continues as the optic tract to the lateral geniculate nucleus, pretectal nuclei, and superior colliculus.

Photoreceptor Cell is a specialized type of cell found in the retina that is capable of visual phototransduction, which is a process by which light is converted into electrical signals in the rod cells, cone cells and photosensitive ganglion cells of the retina of the eye. The great biological importance of photoreceptors is that they convert light (visible electromagnetic radiation) into signals that can stimulate biological processes. To be more specific, photoreceptor proteins in the cell absorb photons, triggering a change in the cell's membrane potential. There are currently three known types of photoreceptor cells in mammalian eyes: rods, cones, and photosensitive retinal ganglion cells. The two classic photoreceptor cells are rods and cones, each contributing information used by the visual system to form a representation of the visual world, sight. The rods are narrower than the cones and distributed differently across the retina, but the chemical process in each that supports phototransduction is similar. A third class of mammalian photoreceptor cell was discovered during the 1990s: the photosensitive ganglion cells. These cells do not contribute to sight directly, but are thought to support circadian rhythms and pupillary reflex. There are major functional differences between the rods and cones. Rods are extremely sensitive, and can be triggered by a single photon. At very low light levels, visual experience is based solely on the rod signal. This explains why colors cannot be seen at low light levels: only one type of photoreceptor cell is active. Cones require significantly brighter light (i.e., a larger numbers of photons) in order to produce a signal. In humans, there are three different types of cone cell, distinguished by their pattern of response to different wavelengths of light. Color experience is calculated from these three distinct signals, perhaps via an opponent process. The three types of cone cell respond (roughly) to light of short, medium, and long wavelengths. Note that, due to the principle of univariance, the firing of the cell depends upon only the number of photons absorbed. The different responses of the three types of cone cells are determined by the likelihoods that their respective photoreceptor proteins will absorb photons of different wavelengths. So, for example, an L cone cell contains a photoreceptor protein that more readily absorbs long wavelengths of light (i.e., more "red"). Light of a shorter wavelength can also produce the same response, but it must be much brighter to do so. The human retina contains about 120 million rod cells, and 6 million cone cells. The number and ratio of rods to cones varies among species, dependent on whether an animal is primarily diurnal or nocturnal. Certain owls, such as the tawny owl, have a tremendous number of rods in their retinae. In addition, there are about 2.4 million to 3 million ganglion cells in the human visual system, 1 to 2% of them photosensitive. The axons of ganglion cells form the two optic nerves. The pineal and parapineal glands are photoreceptive in non-mammalian vertebrates, but not in mammals. Birds have photoactive cerebrospinal fluid (CSF)-contacting neurons within the paraventricular organ that respond to light in the absence of input from the eyes or neurotransmitters. Invertebrate photoreceptors in organisms such as insects and molluscs are different in both their morphological organization and their underlying biochemical pathways. Described here are human photoreceptors.

Rod Cell are photoreceptor cells in the retina of the eye that can function in less intense light than the other type of visual photoreceptor, cone cells. Rods are usually found concentrated at the outer edges of the retina and are used in peripheral vision. On average, there are approximately 90 million rod cells in the human retina. Rod cells are more sensitive than cone cells and are almost entirely responsible for night vision. However, rods have little role in color vision, which is one of the main reasons why colors are much less apparent in darkness.

Cone Cell are one of three types of photoreceptor cells in the retina of mammalian eyes (e.g. the human eye). They are responsible for color vision and function best in relatively bright light, as opposed to rod cells, which work better in dim light. Cone cells are densely packed in the fovea centralis, a 0.3 mm diameter rod-free area with very thin, densely packed cones which quickly reduce in number towards the periphery of the retina. There are about six to seven million cones in a human eye and are most concentrated towards the macula. The commonly cited figure of six million cone cells in the human eye was found by Osterberg in 1935. Oyster's textbook (1999) cites work by Curcio et al. (1990) indicating an average close to 4.5 million cone cells and 90 million rod cells in the human retina. Cones are less sensitive to light than the rod cells in the retina (which support vision at low light levels), but allow the perception of colour. They are also able to perceive finer detail and more rapid changes in images, because their response times to stimuli are faster than those of rods. Cones are normally one of the three types, each with different pigment, namely: S-cones, M-cones and L-cones. Each cone is therefore sensitive to visible wavelengths of light that correspond to short-wavelength, medium-wavelength and long-wavelength light. Because humans usually have three kinds of cones with different photopsins, which have different response curves and thus respond to variation in colour in different ways, we have trichromatic vision. Being colour blind can change this, and there have been some verified reports of people with four or more types of cones, giving them tetrachromatic vision. The three pigments responsible for detecting light have been shown to vary in their exact chemical composition due to genetic mutation; different individuals will have cones with different color sensitivity. Destruction of the cone cells from disease would result in color blindness.

Electro-Magnetic Spectrum

Premature Births

Demodex Eyelash Mites

Mydriasis is the dilation of the pupil, usually defined as when having a non-physiological cause, but sometimes defined as potentially being a physiological pupillary response. Non-physiological causes of mydriasis include disease, trauma, or the use of drugs. Normally, as part of the pupillary light reflex, the pupil dilates in the dark and constricts in the light to respectively improve vividity at night and to protect the retina from sunlight damage during the day. A mydriatic pupil will remain excessively large even in a bright environment. The excitation of the radial fibres of the iris which increases the pupillary aperture is referred to as a mydriasis. More generally, mydriasis also refers to the natural dilation of pupils, for instance in low light conditions or under sympathetic stimulation.

Pupillary Response is a physiological response that varies the size of the pupil, via the optic and oculomotor cranial nerve. A constriction response (miosis), is the narrowing the pupil, or which may be caused by scleral buckles or drugs such as opiates/opioids or anti hypertension medications. A dilation response (mydriasis), is the widening the pupil and may be caused by anticholinergic agents or drugs such as MDMA, cocaine and amphetamines. Dilation of the pupil occurs when the smooth cells of the radial muscle, controlled by the sympathetic nervous system (SNS), contract. Constriction of the pupil occurs when the circular muscle, controlled by the parasympathetic nervous system (PSNS), contracts.

Eye Twitching

Animal Eyes Pupil Shapes

Binocular Vision is vision in which creatures having two eyes use them together.

Spatial intelligence

Onchocerciasis (River Blindness)

Retinal Implant is a Retinal prostheses for restoration of sight to patients blinded by retinal degeneration meant to partially restore useful vision to people who have lost their photoreceptors due to retinal diseases such as retinitis pigmentosa.

Oxford Student Creates first Synthetic Soft Tissue Retina

Visual Prosthesis is a experimental bionic eye visual device intended to restore functional vision in those suffering from partial or total blindness.

Argus Retinal Prosthesis is an electronic retinal implant.


Bevacizumab is sold under the trade name Avastin, is an angiogenesis inhibitor, a drug that slows the growth of new blood vessels.

Diplopia is a Computer Game that has been designed using the latest research to help people with amblyopia (lazy eye) and
strabismus (crossed eyes).

Brain training video games help low-vision kids see better

Computer Vision Syndrome
Protecting your Vision
Digital Detox (technology addiction)

Color Blindness Correction
Why do we See Colors?
Color-Binoculars App helps color blind individuals distinguish colors in their everyday lives

Enchroma vision science and optical technology. The only specialty eyewear that alleviates red-green color blindness, enhancing colors without the compromise of color accuracy.

Orcam is a miniature smart camera that can attach to any pair of glasses. The device takes a photo of words and reads them to the blind.

Brain-sensing technology developed by Stanford scientists allows typing at rate of 12 words per minute, could provide a way for people with movement disorders to communicate.

VoiceOver Gesture Support, Text to Speech, Braille Display Mirroring

Vision Correcting Light Field Display 

Blind Ambition Vision-impaired & Low Vision Tool (youtube)
Daniel Kish: How I use Sonar to Navigate the World (youtube)
How new technology helps blind people explore the world (video and text)

Sonar is a technique that uses sound propagation to navigate, communicate with or detect objects.

SmartCane device is an electronic travel aid which fits on the top fold of the white cane.

BuzzClip, wearable ultrasound for visually impaired people

Music (educational)

Sound Symbolism is the idea that vocal sounds or phonemes carry meaning in and of themselves.

Sounds Create Shapes

The Read 'n Style Pen: Turn any text to audio. The world's first digital reading tool created by and for dyslexics.

Hearing - Testing

Dizzy Head Spins


Braille are patterns of raised dots on a flat surface that represent letters and numerals. A point system of tactile writing designed for the sense of touch.

SyncBraille is one of the smallest, lightest, and most affordable, portable Braille Displays

Refreshable Braille Display is an electro-mechanical device for displaying braille characters, usually by means of round-tipped pins raised through holes in a flat surface.

JAWS Screen Reader is a computer screen reader program for Microsoft Windows that allows blind and visually impaired users to read the screen either with a text-to-speech output or by a refreshable Braille display.

Periscope Braille Tablet

The Elia Idea tactile reading system. An estimated 8.4 million individuals with visual impairment in the US, it is estimated that less than 60,000 can read Braille. High schoolers with visual impairment have a dropout rate of nearly 50%. The employment rate among individuals with sight is approximately 84%. Individuals with visual impairment have an estimated employment rate of 43%; but if the individual can use Braille, that rate soars to 90%. It's estimated that the number of individuals with visual impairment will double to 16 million by 2030.

Human Echolocation is the ability of humans to detect objects in their environment by sensing echoes from those objects, by actively creating sounds – for example, by tapping their canes, lightly stomping their foot, snapping their fingers, or making clicking noises with their mouths – people trained to orient by echolocation can interpret the sound waves reflected by nearby objects, accurately identifying their location and size. This ability is used by some blind people for acoustic wayfinding, or navigating within their environment using auditory rather than visual cues. It is similar in principle to active sonar and to animal echolocation, which is employed by bats, dolphins and toothed whales to find prey.

Shorts: Daniel Kish's echolocation in action (youtube)

Haptic Communication refers to the ways in which people and other animals communicate and interact via the sense of touch. As well as providing information about surfaces and textures, touch, or the haptic sense, is a component of communication in interpersonal relationships that is nonverbal and nonvisual. Touch is extremely important for humans and is vital in conveying physical intimacy. Haptics is a branch of nonverbal communication.

Virtual Reality (haptic)

Morse Code
Sensory Substitution
Brain Plasticity

Talking Barcode Scanners

Sheila Nirenberg: A Prosthetic Eye to treat Blindness (video)
Can Blind People Draw? (youtube)
Ron Mccallum: How Technology allowed me to Read (video)
The Blind Woman Who Saw Rain (youtube)

Suppression of an eye is a subconscious adaptation by a person's brain to eliminate the symptoms of disorders of binocular vision such as strabismus, convergence insufficiency and aniseikonia. The brain can eliminate double vision by ignoring all or part of the image of one of the eyes. The area of a person's visual field that is suppressed is called the suppression scotoma (with a scotoma meaning, more generally, an area of partial alteration in the visual field). Suppression can lead to amblyopia.

Aphantasia: How It Feels To Be Blind In Your Mind

Amazon Echo voice activated search and information.

Information Stations 

Be My Eyes Smartphone App that allows a blind person to use friends and family to help identify things using video.

How Do A Blind Person & A Deaf Person Communicate? (with Rikki Poynter) (youtube)

Lechal Haptic Footwear

Injecting a benign virus that carries good copies of a malformed gene in the retina.

Visual Cortex Activity in Early and Late Blind People

Leber Congenital Amaurosis is an eye disorder that primarily affects the retina, which is the specialized tissue at the back of the eye that detects light and color. People with this disorder typically have severe visual impairment beginning in infancy. The visual impairment tends to be stable, although it may worsen very slowly over time.

Website Tools for Sight Impaired

Computer Accessibility refers to the accessibility of a computer system to all people, regardless of disability type or severity of impairment. The term "accessibility" is most often used in reference to specialized hardware or software, or a combination of both, designed to enable use of a computer by a person with a disability or impairment. Specific technologies may be referred to as assistive technology. Assistive technology promotes greater independence by enabling people to perform tasks that they were formerly unable to accomplish, or had great difficulty accomplishing, by providing enhancements to, or changing methods of interacting with, the technology needed to accomplish such tasks. Due to assistive technology, people with disabilities have an opportunity of a more positive and easygoing lifestyle, with an increase in "social participation," "security and control," and a greater chance to "reduce institutional costs without significantly increasing household expenses. There are many disabilities or impairments that can be a barrier to effective computer use. These impairments, which can be acquired from disease, trauma, or may be congenital, include but are not limited to: Cognitive impairments (head injury, autism, developmental disabilities), and learning disabilities, such as dyslexia, dyscalculia or ADHD. Visual impairment such as low-vision, complete or partial blindness, and color blindness. Hearing-related disabilities including deafness, being hard of hearing, or hyperacusis. Motor or dexterity impairment such as paralysis, cerebral palsy, dyspraxia, carpal tunnel syndrome and repetitive strain injury. Accessibility is often abbreviated as the numeronym a11y, where the number 11 refers to the number of letters omitted. This parallels the abbreviations of internationalization and localization as i18n and l10n respectively.

Smartphone Technologies - Artificial Intelligence

Audio Eye makes digital content more accessible, and more usable, for more people.

Wave Web Aim tool that determines the accessibility of web content for sight impaired.

Accessible 360 - W3C Web Accessibility Initiative (WAI).

Interfaces- Usability

Narrator Text–to–Speech Utility
Read Speaker

Daisy Consortium
KNFB Reader

Voice Browsers - Speech Recognition

Audible Books - Audio Books - Audio Books
E-Books - Audiobooks

Seeing with Sound Augmented Reality - VR
Eye Music: Hearing Colored Shapes

Screen Reader is a form of assistive technology (AT) which is essential to people who are blind, as well as useful to people who are visually impaired, illiterate, or have a learning disability. Screen readers are software applications that attempt to convey what people with normal eyesight see on a display to their users via non-visual means, like text-to-speech, sound icons, or a Braille device. They do this by applying a wide variety of techniques that include for example interacting with dedicated accessibility APIs, using various operating system features (like inter-process communication and querying user interface properties) and employing hooking techniques.

Screen Reader plus keyboard helps blind, low-vision users browse modern webpages. Spatial Recognition Interaction Techniques (SPRITEs).

Web Accessibility refers to the inclusive practice of removing barriers that prevent interaction with, or access to websites, by people with disabilities. When sites are correctly designed, developed and edited, all users have equal access to information and functionality. For example, when a site is coded with semantically meaningful HTML, with textual equivalents provided for images and with links named meaningfully, this helps blind users using text-to-speech software and/or text-to-Braille hardware. When text and images are large and/or enlargeable, it is easier for users with poor sight to read and understand the content. When links are underlined (or otherwise differentiated) as well as colored, this ensures that color blind users will be able to notice them. When clickable links and areas are large, this helps users who cannot control a mouse with precision. When pages are coded so that users can navigate by means of the keyboard alone, or a single switch access device alone, this helps users who cannot use a mouse or even a standard keyboard. When videos are closed captioned or a sign language version is available, deaf and hard-of-hearing users can understand the video. When flashing effects are avoided or made optional, users prone to seizures caused by these effects are not put at risk. And when content is written in plain language and illustrated with instructional diagrams and animations, users with dyslexia and learning difficulties are better able to understand the content. When sites are correctly built and maintained, all of these users can be accommodated without decreasing the usability of the site for non-disabled users. The needs that Web accessibility aims to address include: Visual: Visual impairments including blindness, various common types of low vision and poor eyesight, various types of color blindness; Motor/mobility: e.g. difficulty or inability to use the hands, including tremors, muscle slowness, loss of fine muscle control, etc., due to conditions such as Parkinson's Disease, muscular dystrophy, cerebral palsy, stroke; Auditory: Deafness or hearing impairments, including individuals who are hard of hearing; Seizures: Photo epileptic seizures caused by visual strobe or flashing effects. Cognitive/Intellectual: Developmental disabilities, learning disabilities (dyslexia, dyscalculia, etc.), and cognitive disabilities of various origins, affecting memory, attention, developmental "maturity," problem-solving and logic skills, etc.

Benetech software solutions for people with disabilities to help them read and learn.

Technology Overuse

People with Disabilities are Gifts from God

Eye Color

Eye Color is a polygenic phenotypic character determined by two distinct factors: The pigmentation of the eye's iris and the frequency-dependence of the scattering of light by the turbid medium in the stroma of the iris.

Stroma of the iris is a fibrovascular layer of tissue (vessels and Fibers). It is the upper layer of two in the iris. The stroma is a delicate interlacement of fibres. Some circle the circumference of the iris and the majority radiate toward the pupil. Blood vessels and nerves intersperse this mesh. In dark eyes, the stroma often contains pigment granules. Blue eyes and the eyes of albinos, however, lack pigment. The stroma connects to a sphincter muscle (sphincter pupillae), which contracts the pupil in a circular motion, and a set of dilator muscles (dilator pupillae) which pull the iris radially to enlarge the pupil, pulling it in folds. The back surface is covered by a commonly, heavily pigmented epithelial layer that is two cells thick (the iris pigment epithelium), but the front surface has no epithelium. This anterior surface projects as the muscles dilate.

Iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupil and thus the amount of light reaching the retina. Eye color is defined by that of the iris. In optical terms, the pupil is the eye's aperture, while the iris is the diaphragm that serves as the aperture stop. Prosthetic Iris Devices

Pupil is a hole located in the centre of the iris of the eye that allows light to strike the retina. It appears black because light rays entering the pupil are either absorbed by the tissues inside the eye directly, or absorbed after diffuse reflections within the eye that mostly miss exiting the narrow pupil.

Brown eyes are the most common eye color in the world with over 55% of the world's population having brown eyes.

Hazel eyes are around 5-8% of the world's population. Hazel eyes are similar to brown eyes, although they are typically lighter in color, and have more of a green-yellow tint. Hazel eyes have a higher concentration of melanin (pigment) around the eye's border, which can result in a multi-colored appearance that varies between copper and green depending on the lighting.

Blue eyes are around 8% of the world's population. 

Green eyes are often confused with hazel eye color, yet is entirely separate and distinct. Green eye color is the rarest color found around the world, and it is estimated that only around 2% of the world's population has green colored eyes. Green eye color is a result of a mild amount of pigmentation in the eye with a golden tint. When combined with the natural blue scattering of the eye, the colors mix to give a green appearance. Green eye color is most common in northern and central Europe, but can also be found in western Asian cultures on rare occasion.

Silver eyes are also quite rare. Silver eyes are the result of a very low amount of pigmentation in the eye, which reflects a gray-silver appearance. Amber eyes show off a yellow-copper tone, which results from the yellow colored pigment lipochrome.

Amber eyes are very rare worldwide, and are most common in Asia and South American countries. Amber eye color can range from golden yellow to a more copper tone.

History of Eye Color (timeline)

Grey Hair (why hair color changes)

The Thinker Man