Trachoma is an eye infection caused by a tiny bacterium called Chlamydia trachomatis. Repeated infections over many years make the inside of the eyelids rough ...

Traboulsi syndrome is a very rare, inherited eye condition in which several things tend to happen together. People often have a distinct facial appearance ...

Toxoplasmosis is an infection caused by a tiny parasite called Toxoplasma gondii. This parasite lives in many warm-blooded animals, but cats are the main ...

Toxocariasis is an infection caused by the roundworms Toxocara canis (from dogs) and Toxocara cati (from cats). People get sick after swallowing the ...

Toxic optic neuropathy is a type of damage to the optic nerve that happens because a poison, a harmful drug, or a severe lack of key nutrients hurts the nerve ...

Toxic Anterior Segment Syndrome—usually shortened to TASS—is a sudden, sterile (non-infectious) inflammation inside the front part of the eye after eye ...

Townes-Brocks syndrome (TBS) is a rare, inherited condition that affects how several parts of the body form before birth. Doctors most often recognize TBS by a ...

Torpedo maculopathy is a rare, usually harmless birth-time change in the eye’s retinal pigment epithelium (RPE)—the thin support layer under the seeing cells ...

Topical anesthetic abuse keratopathy is a serious injury to the clear front window of the eye (the cornea) that happens when a person uses numbing eye drops ...

Tolosa–Hunt Syndrome is a rare cause of severe eye pain with weak or frozen eye movements. Doctors call this “painful ophthalmoplegia.” In most people it ...

Graves orbitopathy (also called thyroid eye disease) is an autoimmune eye condition that happens most often in people who have an overactive thyroid due to ...

Tobacco optic neuropathy is a problem of the optic nerve that happens in people who use tobacco for a long time. The optic nerve is the “cable” that carries ...

TNF-alpha related optic neuropathy means damage to the optic nerve that is linked in some way to the tumor necrosis factor-alpha (TNF-α) pathway. In real life, ...

Tilted Disc Syndrome (TDS) is a harmless eye shape difference that a person is born with. It affects the way the optic disc looks. The optic disc (also called ...

Thyroid Eye Disease (also called Graves’ orbitopathy or thyroid-associated ophthalmopathy) is an autoimmune condition where the body’s defense system ...

A thymoma is a growth (tumor) that starts in the cells that line the thymus. These cells are called thymic epithelial cells. In a thymoma, these cells grow ...

Thygeson Superficial Punctate Keratitis—often shortened to TSPK—is a long-lasting, on-and-off inflammation of the front, clear window of the eye called the ...

Cyclovertical muscle palsy is a problem with the eye muscles that move the eye up and down (vertical movement) and also twist the eye a little like a clock ...

Thiel–Behnke corneal dystrophy, sometimes called “honeycomb dystrophy” or corneal dystrophy of Bowman layer, type II (CDB2), is an inherited condition that ...

Corneal hysteresis is a biomechanical property of the cornea. The cornea is the clear, dome-shaped front window of the eye. Biomechanical means “how a living ...