Cogan Syndrome
Cogan syndrome (often written “Cogan’s syndrome”) is a rare autoimmune disease in which the body’s own defense system mistakenly attacks tissues of the inner ear, eyes, and sometimes large blood ...
Rx Eye & Vision Care (A – Z)
Valley Fever
Valley Fever—known to doctors as coccidioidomycosis—is an infection you catch by breathing in microscopic fungal spores that float up from dry, dusty soil in parts of the Americas, especially the ...
Coccidioidomycosis
Coccidioidomycosis—often called Valley Fever—is a fungal infection caused by breathing in microscopic spores of Coccidioides fungi that live in certain desert soils, mainly in the southwestern United ...
Cobalamin C (cblC) Deficiency
Cobalamin C (often written cblC) deficiency is the single most common inherited error in the way our cells handle vitamin B₁₂. It sits at the crossroads of two larger problems—methyl‑malonic acidemia ...
Coats Disease
Coats disease is an uncommon, non‑hereditary eye disorder in which the tiny blood vessels (capillaries) inside the retina become abnormally dilated, twisted, and leaky. These unhealthy vessels ooze ...
Cytomegalovirus (CMV) Retinitis
Cytomegalovirus (CMV) retinitis is a severe viral infection of the retina – the light‑sensing tissue at the back of the eye. CMV belongs to the herpes‑virus family. In most healthy people it hides ...
Cytomegalovirus (CMV) Endotheliitis
Cytomegalovirus (CMV) endotheliitis is a sight‑threatening eye infection in which human CMV invades the corneal endothelium—the single‑cell‑thick layer that pumps fluid out of the cornea to keep it ...
Clear Lens Extraction
Clear Lens Extraction (CLE) — sometimes called refractive lens exchange, refractive lensectomy or custom lens replacement — is a surgical technique in which the eye’s natural crystalline lens is ...
Cicatricial Ectropion
Cicatricial ectropion means the eyelid—usually the lower lid—turns outward because scar tissue (a “cicatrix”) shortens or contracts the skin, pulling the lid away from the eye. That outward sag ...
Cicatricial Conjunctivitis
“Cicatricial” is another word for “caused by a scar.” “Conjunctivitis” means inflammation of the conjunctiva―the thin, clear membrane that covers the white of your eye and lines the inside of your ...
Chronic Relapsing Inflammatory Optic Neuritis
Chronic Relapsing Inflammatory Optic Neuritis—usually shortened to CRION—is a rare, immune‑mediated disease in which the optic nerve keeps becoming inflamed, calms down with treatment, and then ...
Chronic Progressive External Ophthalmoplegia
Chronic Progressive External Ophthalmoplegia is a slow‑moving muscle disease in which the tiny muscles that lift your eyelids and move your eyes lose power over many years. Most people notice heavy, ...
Chromatopsia
Chromatopsia is an acquired disturbance of colour vision in which everything in the visual field looks as though it has been dipped in one dominant tint, while the basic outlines and brightness of ...
Choroideremia
Choroideremia (pronounced kuh‑ROY‑der‑EE‑mee‑ah) is a rare, inherited eye disease that slowly robs people—mostly males—of their sight. It starts with night‑blindness in childhood, then eats away at ...
Choroidal Macroaneurysm
Choroidal macroaneurysms (CMAs) are balloon‑like bulges that form in the arteries of the choroid, the dense, blood‑rich layer that sits just behind the retina. They behave like tiny “pouches” on the ...
Choroidal Macrovessels Disorder
A choroidal macrovessel (CM) is an unusually large, tortuous blood vessel inside the choroid, the vascular layer that lies between the retina and the sclera. Under normal circumstances the choroid is ...
Choroidal Posterior Vortex Veins Disorder
Choroidal Posterior Vortex Veins Disorder describes a group of anatomical variations and malfunctions in the vortex‑vein drainage system of the choroid, especially when one or more vortex veins exit ...
Choroidal Vascular Anomalies
Choroidal vascular anomalies are a group of eye problems in which the network of blood vessels inside the choroid—the richly‑supplied, brick‑red layer that sits between the retina and the outer white ...
Choroidal Rupture
A choroidal rupture is a tear that runs through three delicate, layered tissues at the back of the eye: the choroid (the blood‑rich layer that feeds the retina), Bruch’s membrane (a thin supporting ...
Choroidal Osteoma
A choroidal osteoma is an unusual, non‑cancerous growth made of true, mature bone that forms inside the choroid—the vascular, brown‑red layer lying between the retina and the white sclera of the eye. ...
