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 articleAtypical X-linked achromatopsia is a rare eye disease that affects how the cone cells in the retina work. Cone cells help us see fine detail and...
Read articleCone monochromatism is a rare eye problem where a person has only one working type of cone cell in the retina, instead of three different cone...
Read articleRetinal cone dystrophy type 3B is a very rare inherited eye disease that mainly damages the cone cells in the retina, which are the light-sensitive cells...
Read articleCone dystrophy with supernormal scotopic electroretinogram is a rare, inherited eye disease that mainly damages the cone cells in the retina, and later also affects the...
Read articleCone dystrophy with supernormal rod electroretinogram is a rare eye disease that damages the light-sensing cells in the retina, especially the cone cells in the center...
Read articleCone dystrophy with supernormal rod response (CDSRR) is a very rare inherited eye disease where the cone cells in the retina slowly stop working properly, and...
Read articleChorioretinopathy syndrome is a general name for eye diseases that damage both the retina (the light-sensing layer) and the choroid (the blood-vessel layer under the retina)....
Read articleMacular atrophy-chorioretinopathy syndrome is a very rare eye disease present from birth. In this disease the back part of the eye (the retina) and the layer...
Read articleColobomatous optic disc-macular atrophy-chorioretinopathy syndrome is a very rare, inherited eye disease. In this condition, the nerve head at the back of the eye (optic disc)...
Read articleColoboma of the optic papilla means there is a “hole” or deep pit in the optic disc (optic nerve head) that is present from birth. The...
Read articleColoboma of the optic nerve means there is a small “missing piece” or deep hole in the tissue where the optic nerve meets the back of...
Read articleCongenital coloboma of the macula lutea (macular coloboma) is a rare eye problem that is present from birth. In this condition, some of the normal tissue...
Read articleColoboma of the macula (macular coloboma) is a rare birth problem of the eye in which a piece of the macula is missing or badly formed....
Read articleColoboma of the choroid and retina (often called chorioretinal coloboma) is a birth defect of the back part of the eye. In this condition, there is...
Read articleNodular unilateral glaucoma is a description, not an official single disease name. It usually means glaucoma in one eye (unilateral) that is caused or worsened by...
Read articleCogan-Reese syndrome is a very rare eye disease. It affects the clear front window of the eye (the cornea), the colored part (the iris), and the...
Read articleCerebroretinal microangiopathy with calcifications and cysts is a very rare inherited disease that mainly damages the tiny blood vessels in the brain and the back of...
Read articleChoroiditis means inflammation in the choroid, which is a thin, rich blood-vessel layer under the retina at the back of the eye. This layer feeds the...
Read articleTapetochoroidal dystrophy is another name that has been used for choroideremia, an inherited eye disease that slowly damages the light-sensing retina and the layer under it...
Read articleChoroideremia is a rare eye disease that slowly takes away sight over many years. It mainly affects boys and men because the problem gene is on...
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