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 articleCongenital iris ectropion is more commonly called congenital ectropion uveae. It is a rare developmental eye condition present from birth in which the dark pigment layer...
Read articleCongenital cystic eyeball, also called congenital cystic eye, is a very rare birth defect in which a cyst forms in the eye socket and the normal...
Read articleCongenital anophthalmos with cyst is a very rare birth defect of eye development. In this condition, a child is born without a normally formed eye in...
Read articleCongenital cystic eye is a very rare birth condition. In this condition, a cyst-like sac grows in the eye socket where the eye should normally form....
Read articleCerulean cataract is a rare kind of childhood or developmental cataract. A cataract means the natural lens of the eye becomes cloudy instead of staying clear....
Read articleCongenital blue dot cataract, also called cerulean cataract, is a type of childhood lens opacity in which many tiny bluish or whitish dots appear in the...
Read articleCongenital achiasma is a very rare eye and brain problem that is present from birth. It happens when the optic chiasm, the “cross-road” where nerve fibers...
Read articleCongenital absence of lacrimal puncta and salivary glands means that a baby is born without the tiny tear drainage openings on the eyelids (lacrimal puncta) and...
Read articleAplasia of the lacrimal and salivary glands means that the tear glands and saliva glands did not grow properly before birth. They are partly formed, very...
Read articleCone-rod dystrophy type 6 (often written as CORD6) is a rare eye disease that slowly damages the light-sensing cells (cones and rods) in the retina, the...
Read articleCone-rod dystrophy from ABCA4 mutation is a rare, inherited eye disease that slowly damages the light-sensing cells (cones first, then rods) in the retina. The ABCA4...
Read articleCone-rod retinal dystrophy caused by a CRX mutation is a rare inherited retinal disease. It happens when a disease-causing change in the CRX gene damages the...
Read articleCone-rod dystrophy type 2 is a genetic eye disease where cone cells (for central vision, color, fine detail) and later rod cells (for night and side...
Read articlePRPH2-related cone-rod dystrophy is a rare, inherited eye disease that damages the light-sensitive cells (cones and rods) in the retina because of harmful changes (mutations) in...
Read articleCone-rod retinal dystrophy is a rare genetic eye disease that slowly damages the light-sensing cells (cones first, then rods) in the retina, the thin layer at...
Read articleCone-rod degeneration (also called cone-rod dystrophy) is a rare, inherited eye disease that slowly damages the light-sensitive cells (photoreceptors) in the retina. First, the cone cells...
Read articleCone-rod dystrophy (CRD) is a group of rare genetic eye diseases where cone cells (for central, color, and daytime vision) are damaged first and rod cells...
Read articleX-linked incomplete achromatopsia is a rare inherited eye disorder present from birth. It mainly affects the cone cells in the retina, which are the cells that...
Read articleBlue mono-cone monochromatic type colorblindness is usually called blue cone monochromacy (BCM). It is a rare, inherited eye disease. In this condition, the red cones and...
Read articleBlue cone monochromatism, also called blue cone monochromacy, is a rare inherited eye disease present from birth. In this condition, the red-sensing cones and green-sensing cones...
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