The vocabulary of low vision.

Full glossary

A

ADA (Americans with Disabilities Act)

US federal civil-rights law (1990) prohibiting discrimination against people with disabilities. Requires reasonable accommodations at work, in public spaces and in commerce.

AFB (American Foundation for the Blind)

National research and advocacy organization founded in 1921. Helen Keller served as a long-time advocate. Publishes resources and policy analysis on blindness.

AMD (Age-related Macular Degeneration)

Leading cause of blindness after 65 in developed countries. The macula degenerates, causing loss of central vision while peripheral vision is preserved. Two forms: dry (80%) and wet (20%, faster but treatable). Lumyeye for AMD →

APH (American Printing House for the Blind)

Federally designated nonprofit (1858) that produces educational materials, braille books and adaptive technology for students with visual impairments.

AT (Assistive Technology)

Any device, software or service that helps a person with a disability live and work more independently. Lumyeye is a software-based assistive technology for vision.

Atrophic macular degeneration

Dry, late-stage form of AMD marked by progressive loss of macular cells. A central blind spot appears in the field of view.

Visual acuity

Ability to discern fine detail. Measured by the Snellen scale (20/20 reference) or in logMAR. Legal blindness in the US is defined as central vision 20/200 or worse with correction in the better eye, or a visual field of 20° or less.

B

BlindShell

Specialized push-button phone designed for blind users. Simplified interface, no touchscreen. BlindShell vs iPhone →

Braille

Tactile six-dot writing system invented by Louis Braille in 1825. Read by touch. Today used by roughly 10% of blind users (US figures comparable to French ones).

Braille display

Refreshable tactile device that renders screen content in braille via pins that rise and fall. Expensive: typically $2,000-$8,000.

C

Cataract

Progressive clouding of the natural lens. Causes blurry vision and halos around lights. Treatable by surgery. Lumyeye for cataract →

CCTV (electronic magnifier)

Closed-Circuit Television magnifier, a desktop or portable device that enlarges text and objects on a screen. Typically $700-$2,800. Lumyeye offers a much cheaper software alternative.

Color blindness

Anomalous color perception, usually red-green confusion. Affects about 8% of men. Distinct from low vision.

Crystalline lens

Transparent lens behind the iris that focuses light on the retina. Clouds with age (cataract).

D

Deafblindness

Combined visual and hearing impairment. Often associated with Usher syndrome. Requires specialized accommodations (tactile braille, support service providers).

Diabetes

Chronic disease that can cause diabetic retinopathy, the leading cause of new-onset blindness in working-age US adults.

Diabetic retinopathy

Damage to the retinal blood vessels caused by diabetes. Leading cause of new blindness in adults aged 20-65. Lumyeye for diabetic retinopathy →

E

Envision Glasses

Smart glasses for visual assistance, around $1,899. Recognize text, objects and faces. Lumyeye alternative →

Esotropia

Inward-turning strabismus. May affect binocular vision and depth perception.

F

G

Gemini Live

Google's multimodal AI used by Lumyeye Pro for Vision Live: real-time video streaming plus voice Q&A.

Glaucoma

Optic-nerve disease frequently associated with elevated intraocular pressure. Progressive loss of peripheral field of view, leading to tunnel vision. Lumyeye for glaucoma →

Guide dog

Dog trained at a specialized school to guide a blind person while traveling. In the US, organizations like The Seeing Eye and Guide Dogs for the Blind provide dogs at no cost after joint training with the handler.

H

Hemianopia

Loss of half the visual field (left, right, upper, lower). Most often after a stroke. Can be homonymous (same side in both eyes) or heteronymous.

I

IDEA

Individuals with Disabilities Education Act. US federal law governing special education from birth to age 21, including IEPs for students with visual impairments.

IEP (Individualized Education Program)

A written plan for a public-school student receiving special education services, including accommodations for blind and low-vision learners.

iOS 17.6+ or Android 9+

Minimum versions for Lumyeye Pro: iOS 17.6+ on iPhone or Android 9+ on a compatible Android phone. Vision Live uses the camera.

Generative AI

AI capable of producing text, voice or image (Gemini, GPT, Claude). Technological core of Lumyeye Pro for scene description and voice conversation.

L

Legal blindness

In the US: central vision 20/200 or worse with best correction in the better eye, or visual field 20° or less. Used to determine eligibility for benefits, tax deductions and rehab services.

Low vision

Best-corrected acuity between 20/70 and 20/200, not improvable by glasses, contacts or surgery. About 7.3 million people are affected in the US.

M

Macula

Central area of the retina, dense in cones, responsible for fine vision and color perception. Target of AMD.

MyEye (OrCam)

OrCam device: a camera clipped onto eyeglass arms, around $3,500-$4,250. Lumyeye alternative →

N

NFB (National Federation of the Blind)

Largest US membership organization of blind people. Advocacy, mentoring, scholarships, and the BLIND, Inc. training programs.

Nystagmus

Involuntary, rhythmic eye movement. Can be congenital or acquired. Reduces acuity and image stability.

O

OCR (Optical Character Recognition)

Recognition of printed characters. Turns text in an image into spoken text. Functional core of Lumyeye Classic.

Ophthalmologist

Medical doctor specializing in the eye and vision. Diagnoses ocular conditions and prescribes treatments.

Optometrist

Healthcare professional who provides eye exams, prescribes corrective lenses and can detect some ocular conditions. Refers to an ophthalmologist when needed.

Orientation & Mobility (O&M)

Set of techniques used by blind users to navigate safely: white cane, environmental landmarks, route memorization, guide dog. Taught by certified O&M specialists.

P

Photophobia

Excessive sensitivity to light. Common symptom of retinal disease (RP, achromatopsia).

R

Retina

Light-sensitive membrane lining the back of the eye. Contains photoreceptors (cones and rods) that convert light into a neural signal.

Retinitis pigmentosa (RP)

Hereditary disease causing photoreceptor degeneration. Typical course: night blindness, then tunnel vision, then blindness.

Diabetic retinopathy

Damage to the retinal vessels caused by diabetes. Leading cause of new blindness in working-age US adults. Lumyeye for diabetic retinopathy →

S

Scotoma

A blind spot in the visual field, central (typical in AMD) or peripheral (typical in glaucoma).

Section 504

Section 504 of the Rehabilitation Act of 1973. Prohibits discrimination against people with disabilities in any federally funded program, schools, hospitals, employers.

Seeing AI

Free Microsoft app for blind users. Reads text, identifies objects, describes scenes. Lumyeye alternative →

SiriKit

iOS framework that lets an app integrate with Siri. Lumyeye Pro uses it to launch the app by voice.

Stargardt disease

Juvenile, hereditary form of macular degeneration. Typically appears between ages 6 and 20. Slow progression toward loss of central vision.

T

TalkBack

Native Android screen reader. The equivalent of VoiceOver on iOS. Reads screen content and touch interactions aloud.

TTS (Text-to-Speech)

Speech synthesis: turning written text into spoken voice. Lumyeye Pro ships a warm, natural-sounding voice for most interactions, while remaining deeply integrated with VoiceOver for those who use it.

TVI (Teacher of the Visually Impaired)

Certified specialist who works with blind and low-vision students in K-12 schools, often through an IEP.

Tunnel vision

Vision restricted to a narrow central circle, as if looking through a tube. Characteristic of advanced glaucoma and retinitis pigmentosa.

U

Usher syndrome

Rare hereditary syndrome combining retinitis pigmentosa with hearing loss.

V

VoiceOver

Apple's native iOS screen reader, designed for blind users. Lumyeye Pro is deeply integrated with VoiceOver (months of work) while also offering its own warm, natural voice for most interactions, you choose whichever feels right.

Central vision

High-resolution vision served by the macula. Used for reading and face recognition. Affected by AMD and Stargardt.

Vision Live

Lumyeye Pro exclusive: live video streaming plus real-time voice Q&A. You film your surroundings and ask questions ("what's in front of me?", "is someone there?"); Lumyeye Pro answers from what it sees. An on-demand Q&A session about the visual environment.

Peripheral vision

Vision outside the macula. Detects movement and gives a broad sense of space. Affected by glaucoma and retinitis pigmentosa.

Z

ZoomText

Screen magnification software for desktop computers, designed for low-vision users. Around $700.