Causes of Blindness and Visual Impairment

This section connects the user to information about the causes of blindness and visual impairment. The Introduction and Overview section links to more general information, while the Diseases and Disorders section has sites with more detail about specific conditions, including symptoms, causes, diagnosis, prevention, treatment, and support groups. The Signs of Vision Disorders category advises the user about symptoms to be on the watch for.
Below is a list of topics you'll find in this section. Click on a title to jump to a specific topic.


Blindness and Visual Impairment: Introduction and Overview

National Institute of Health
This US Government institute's site provides definitions, illustrations, causes of blindness, and advice on when to contact a medical professional.
Sightsavers International
In-depth illustrated descriptions of global causes of blindness and their treatments.
National Federation of the Blind (NFB)
A dictionary of common medical conditions that cause visual impairment in the U.S., explained in non-clinical language accessible to the layperson.
World Health Organization (WHO)
Statistics and distribution data on global blindness.
World Health Organization (WHO)
Information on the most prevalent eye diseases globally, and WHO's work to eradicate them.
Good introductory information on a number of eye conditions, including those that do not cause visual impairment.
National Eye Institute
This site has overviews on many vision conditions.
American Optometric Association (AOA)
Symptoms and risk factors of eye and vision conditions.
This site has short definitions of many vision disorders and a few words about treatment and assistive technology. Includes links to support groups for the specific disorder or condition.
Foundation Fighting Blindness
Information on causes of and treatments for retinitis pigmentosa (RP), macular degeneration, usher syndrome, and the entire spectrum of retinal degenerative diseases.
Information on eye conditions, including both common and rare ones.
Listing of eye conditions, with introductory information and links to support organizations and more information.
Vision Australia
Information on more than a dozen common causes of blindness and low vision.
New York Institute for Special Education
A wealth of information about eye diseases and conditions, including links to many resources.
Department of Ophthalmology, Algemeen Ziekenhuis, Sint-Jozef, Turnhout, Belgium
The main causes of blindness and visual disabilities worldwide, many of which are preventable. Downloads as a pdf (requires Adobe Acrobat Reader).
The Low Vision Gateway
Descriptions of many eye diseases and conditions; links to related support groups.
American Association for Pediatric Ophthalmology and Strabismus (AAPOS)
Frequently Asked Questions (FAQs) regarding specific visual conditions are composed and periodically reviewed by pediatric ophthalmologists and certified orthoptists from the Public Information Committee of AAPOS. For questions or suggestions regarding FAQs please contact us.  Some terms are available in English, Chinese, and Spanish.

Blindness and Visual Impairment: Organizations and Resources to Explore

This coalition of 55 professional, consumer, and industry organizations involved in eye and vision research works to achieve the best eye and vision care for all Americans through advocacy and public education.

Diseases and Disorders That Cause Blindness and Visual Impairment

Below is a list of topics you'll find in this section. Click on a title to jump to a specific topic.

Age-Related Macular Degeneration (AMD or ARMD)

An overview, including signs and symptoms, an online video exploring adaptive technology, and additional resources.
Sacramento Network of Care
Causes, symptoms, diagnosis, and treatment of age-related macular degeneration, and suggestions for living with it.
National Eye Institute
This fact-filled introduction to age-related macular degeneration includes an update on current research. Also available as an audio file.
Vision 2020
An exploration of the global prevalence of age-related macular degeneration.
Bright Focus Foundation
Formerly the American Health Assistance Foundation, Bright Focus provides consumer-friendly information about visual impairments like macular degeneration and glaucoma.
Prevent Blindness America
An introduction to age-related macular degeneration, with an overview of promising treatments and suggestions on living with the disease.
Edel Optics
Overview of AMD, with symptoms, information on diagnosis, diet & nutrition, and related resources.

Age-Related Macular Degeneration (AMD or ARMD): Organizations and Resources to Explore

Information for people with age-related macular degeneration, their families, caregivers, and professionals.
A wide array of information and resources.
The online newsletter on this site offers updates on research findings and practical tips for people with age-related macular degeneration.
Free information and personal assistance for people dealing with macular degeneration and similar retinal diseases.


National Organization of Albinism and Hypopigmentation (NOAH)
Links to information about albinism, including issues specific to children, students, and medical patients who have albinism.


Prevent Blindness America
Definition of amblyopia, causes and treatment


Information about aniridia and living with the condition.

Batten's Disease

Advance for Nurses
Batten's is an inherited fatal neurodegenerative disease which includes loss of vision. Resources, support, and advice for accommodations.


National Eye Institute
Causes, risk factors, symptoms, treatment, and current research on cataracts.
Sacramento Network of Care
This article explores the pros and cons of surgery, includes suggestions for daily living.
This site includes a searchable knowledgebase, an Ask the Doctor forum, videos, news, and article reviews.
Laser Eye Surgery Hub
This site provides an overview, statistics, recommended articles about Cataracts.

CHARGE Syndrome

Information about CHARGE Syndrome, including special resource packets for new parents and professionals, a one-page fact sheet, a list of frequently asked questions, a newsletter, information on medical management, and online resources.
Perkins eLearning, Perkins School for the Blind
Perkins provides a series of webcasts that explore in-depth the special educational, developmental, and social issues for individuals with CHARGE Syndrome. This link takes you to a landing page of webcasts, and 2 tutorial offerings for continuing education credits.

Cortical Visual Impairment (CVI)

Perkins eLearning Webcast
This webcast featuring Dr. Christine Roman-Lantzy provides information about the specific characteristic behaviors of CVI and provides information regarding the evaluation of functional vision.
Blind Babies Foundation
An overview of CVI, including characteristics and teaching strategies
By Dr. Mary T. Morse
This article cautions against oversimplification of a complex condition, which is not an eye condition but a brain condition. Morse notes that all children with CVI do not exhibit the same behavior, a single approach does not work for all children, and treatment is a dynamic process. 
West Virginia Department of Education
Numerous videos by Dr. Christine Roman-Lantzy on CVI, including an Overview of CVI, CVI Range, Strategies and Programming Planning and more.
Perkins eLearning (Webinar)
In two one-hour sessions, the staff of the New England Eye Low Vision Clinic at Perkins dive deeply into the causes and impacts of cortical/cerebral visual impairments, and discuss the importance of collaborative care for children with CVI.
Texas School for the Blind and Visually Impaired
This three-part multimedia presentation covers an introduction to CVI, case studies, and intervention strategies.
Simplified Technology, Linda J. Burkhart
How to help children with CVI develop neurological pathways to make sense of what they see. Includes design adaptations and strategies to enhance vision, cognition and communication.
Paths to Literacy
Numerous tips, activities, and resources to adapt books and literacy materials for children with CVI.
California Deaf-Blind Services
This fact sheet offers an introduction to neurological and cortical visual impairment, including a list of suggested instructional strategies.
Pennsylvania Training & Technical Assistance Network (PaTTAN)
24-page document has practical suggestions for early intervention, and strategies for pre-school, elementary, and high school; includes students with multiple disabilities.
By Donna Shaman, MOT
Written by an Occupational Therapist (OT), this 80-page document includes an overview of CVI, and information on the evaluation and education of children with CVI.

Cortical Visual Impairment: Organizations and Resources to Explore

Perkins eLearning
Information and resources on CVI, including videos, online classes, and information on the CVI Endorsement.
American Printing House for the Blind (APH)
Information on all aspects of cortical visual impairment (CVI), including introductory materials, CVI products, research, and resources.
National Consortium on Deaf-Blindness (NCDB)
Includes articles, bibliographies and Internet resources.

Diabetic Retinopathy

Symptoms of diabetic retinopathy and links to additional resources
Sacramento Network of Care
Information about treatment of diabetic retinopathy, tips for living with the condition


A comprehensive source of up-to-date news and information about glaucoma.
Vision Aware
Basic information and links to additional resources about glaucoma.
Sacramento Network of Care
An overview of glaucoma and suggestions for living well with it.
Bright Focus Foundation
Formerly the American Health Assistance Foundation, Bright Focus provides consumer-friendly information about visual impairments like macular degeneration and glaucoma.

Glaucoma: Organizations and Resources to Explore

This site includes a searchable knowledgebase, an Ask the Doctor forum, videos, news, and article reviews.
Diagnosis and treatment of glaucoma; links to an online newsletter.
Information on glaucoma's impact on vision, living with the disease, treatment, and research.

Hemispherectomy and Temporo-Parietal-Occipital Disconnection (TPO Disconnection)

This guide summarizes the various visual impairments a child will have after hemispherectomy, TPO disconnection, and occipital lobectomy, and how they can affect a child’s daily living, functional mobility, and access to the educational curriculum in school.

Leber's Congenital Amaurosis (LCA)

Leber’s Congenital Amaurosis (LCA) is a rare, hereditary disorder that leads to retinal dysfunction and visual impairment at an early age – often from birth. Of all the retinal degenerations, LCA has the earliest age of onset and can be the most severe. The Foundation Fighting Blindness provides information and resources regarding LCA.

Leber's Hereditary Optic Neuropathy (LHON)

Families affected by this condition often refer to it as "the other Lebers" -- Leber's Hereditary Optic Neuropathy, a sudden, painless loss of central vision. About 100 people in the United States lose central vision due to LHON each year; thousands more carry a LHON genetic mutation, and they could suddenly lose their vision at any time.
Learn more about LHON causes, diagnosis and treatment through this informative website, and meet LHON families working together to provide support, services, and awareness.


Basic description of nystagmus, FAQs, information for parents of school-age children with the condition.

Optic Nerve Atrophy

U.S.National Library of Health- Pubmed Health
Information on Optic Nerve Atrophy disorder, symptoms, behaviors, research and links to related sites.

Retinopathy of Prematurity
Information about the causes and treatments of the leading cause of blindness in children.

Signs of Vision Disorders

Optometrists Network
A questionnaire for determining whether a vision evaluation is needed; includes links to related topics such as pediatric care, vision therapy, vision checklists and learning disabilities.
Symptoms of poor vision: changes in appearance of the eye and some behavioral indications.
A list for family members and friends of elders who might be experiencing vision disorders.
Prevent Blindness America
Symptoms of eye and vision conditions; information about potentially serious ones.