Browse plain-English disease and condition guides, including symptoms, causes, diagnosis, treatment options, prevention, and when to seek medical care.
Persistent Hyperplastic Primary Vitreous (PHPV)—now more often called Persistent Fetal Vasculature (PFV) is a congenital (present at birth) eye condition. In a developing baby, the eye has...
Read articleAblepharon-Macrostomia Syndrome (AMS) is an extremely rare, autosomal dominant genetic disorder characterized principally by absent or underdeveloped eyelids (“ablepharon”) and an unusually wide, fish-like mouth (“macrostomia”)...
Read articleAcanthamoeba keratitis is a rare but potentially sight-threatening corneal infection caused by the free-living amoeba Acanthamoeba, which is found ubiquitously in soil, fresh water, and even...
Read articleAccommodative esotropia is a common form of childhood strabismus in which one or both eyes turn inward (esodeviation) because of excessive focusing (accommodation) linked to farsightedness...
Read articleAchromatopsia is a rare eye condition that affects how a person sees color. People with achromatopsia typically have trouble seeing colors or can only see them...
Read articleAchromatopsia is a rare, inherited vision disorder that causes a complete or partial inability to see color. People with achromatopsia rely almost entirely on their rod...
Read articleAchromatopsia 2 (ACHM2) is a genetic eye condition that starts from birth. It mainly affects the cone cells in the retina, which are the light-sensing cells...
Read articleAcquired Developmental Prosopagnosia, often referred to as ADP, is a condition that affects a person’s ability to recognize faces. It’s a complex condition, and in this...
Read articleAcquired ectropion uveae (AEU) is a condition in which the pigmented posterior layer of the iris—normally hidden on the back surface—becomes adherent to and everts onto...
Read articleAcquired oculomotor nerve palsy is a non-congenital condition in which the third cranial nerve (oculomotor nerve) becomes damaged after birth, leading to dysfunction of most extraocular...
Read articleAcquired ophthalmoparesis is a condition characterized by weakness or paralysis of one or more extraocular muscles—those that control eye movements—due to processes that occur after birth....
Read articleAcquired Orbital Dysmorphia (AOD) is a medical condition that affects the structure and appearance of the eye socket and surrounding areas. In simpler terms, it means...
Read articleAutosomal dominant vitreoretinochoroidopathy (ADVIRC) with nanophthalmos is a rare, inherited eye disorder. “Autosomal dominant” means a single changed gene from one parent can cause the condition in...
Read articleAutosomal Dominant Vitreoretinochoroidopathy—usually shortened to ADVIRC—is a very rare, inherited eye disease caused by a change (pathogenic variant) in the BEST1 gene. It mainly affects the...
Read articleRhegmatogenous retinal detachment happens when a tear or hole in the retina lets the eye’s gel (vitreous) leak under the retina. Fluid collects under the retina...
Read articleOptic Atrophy-Hearing Loss-Polyneuropathy-Myopathy Syndrome is a pattern of problems caused by faulty cell “power plants” (mitochondria) or proteins that shape and maintain them. The optic nerve...
Read articleAutosomal dominant optic atrophy and peripheral neuropathy syndrome is a rare genetic condition where the optic nerves (the cables that carry visual signals from the eyes...
Read articleAutosomal dominant optic atrophy with peripheral neuropathy (ADOA-PN / “DOA+ with neuropathy”) is a rare genetic disorder. It mostly damages the optic nerve, the cable that...
Read articleVitreoretinopathy is an umbrella term for diseases where the vitreous gel (the clear jelly filling the eye) and the retina (the light-sensing layer lining the back...
Read articleRetinitis proliferans is an old medical term that means new, abnormal blood vessels growing on the retina. The retina is the light-sensing layer at the back...
Read articleCAPN5 vitreoretinopathy is a rare, inherited eye disease caused by harmful changes (variants) in the CAPN5 gene. The disease follows an autosomal dominant pattern—one altered copy...
Read articleOculomotor apraxia (OMA) means the brain has trouble starting fast eye movements called saccades, especially when trying to look to the side on purpose. People often...
Read articleChorioretinal dystrophy is a group of inherited eye conditions in which the retina (the light-sensing layer) and the choroid (the blood-rich layer behind the retina) slowly...
Read articleAtaxia with oculomotor apraxia type 3 is a very rare, inherited brain and nerve disorder. “Ataxia” means poor balance and clumsy, unsteady movements. “Oculomotor apraxia” means...
Read articlePNKP oculomotor apraxia is a rare, inherited brain and nerve disorder. It mainly affects how the eyes start a quick movement called a “saccade.” In daily...
Read articleAtaxia-oculomotor apraxia type 4 (AOA4) is a rare, inherited brain and nerve disorder. It mainly harms the cerebellum (the balance and coordination center) and nearby wiring....
Read articlePoretti-Boltshauser syndrome (PBS) is a rare, autosomal recessive neuro-ophthalmologic disorder caused by pathogenic variants in the LAMA1 gene, which encodes laminin α1, a structural protein essential...
Read articleBlepharochalasis is a rare eyelid condition where the eyelids swell from time to time without pain. These “attacks” usually start in childhood or the teen years....
Read articleAscher syndrome is a very rare, benign condition. It is best known for a “triad” of three findings: repeated swelling and loosening of the upper eyelids...
Read articleLethal ataxia with deafness and optic atrophy (Arts syndrome) is a rare, inherited metabolic–neurologic disease. Babies—usually boys—develop weak muscle tone, poor balance and coordination (ataxia), severe...
Read articleAnterior segment dysgenesis (ASD) is a group of birth-time eye problems where the front parts of the eye—the cornea, iris, lens, drainage angle, and ciliary body—do...
Read articleIridogoniodysgenesis means the colored part of the eye (the iris) and the drainage angle inside the eye (iridocorneal angle or “gonio” region) did not develop normally...
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