Sunrise Syndrome is a complication after cataract surgery in which the artificial lens (intraocular lens, or IOL) slides or sits too high in the eye (a ...

“Unilateral neuralgiform headache” is a group name for very short, very sharp, one-sided head pain attacks. The pain is strictly on one side of the head or ...

SUNCT is a rare headache condition. The name tells you the main features: Short-lasting, Unilateral (one-sided), Neuralgiform (sharp, electric-like) headache ...

A subperiosteal hematoma is a pocket of blood that gathers under the periosteum. The periosteum is a thin, tough sheet that covers the outside of every bone. ...

Subepithelial Mucinous Corneal Dystrophy (SMCD) is an extremely rare inherited eye condition that mainly affects the front clear window of the eye (the ...

Subepidermal calcinosis means tiny deposits of calcium salts just under the outer layer of your skin. Doctors often call the classic form a subepidermal ...

A subconjunctival hemorrhage is a small bleed that happens under the clear skin that covers the white part of your eye, and this clear skin is called the ...

Subclavian Steal Syndrome (SSS) happens when a blockage or severe narrowing in the subclavian artery (the big artery that supplies your arm) “steals” blood ...

Diabetic macular edema (DME) is swelling in the very center of the retina (the macula) caused by diabetes. High blood sugar and related changes make the tiny ...

A stye is a small, painful, red lump on the eyelid. It happens when a tiny oil or sweat gland at the edge of the eyelid gets blocked and then infected, most ...

Sturge–Weber syndrome is a rare condition that a person is born with. It affects blood vessels in the skin of the face, in the thin covering of the brain (the ...

Strachan’s disease is a rare nerve and eye disorder. It mainly affects three systems at the same time. The eyes get a type of optic nerve damage that causes ...

Strabismus means the two eyes are not lined up. One eye points in a slightly different direction than the other eye. Thyroid Eye Disease (TED) is an autoimmune ...

Strabismus fixus is a severe, “stuck” form of eye misalignment. One or both eyes are held in an abnormal position and cannot move normally because something is ...

Straatsma syndrome is a rare eye condition where one eye has three things together: a white, feathery patch on the retina called myelinated retinal nerve ...

Stickler syndrome is a genetic condition that affects the eyes, ears, face, joints, and spine. “Genetic” means the change starts in a gene, which is like a ...

Stevens-Johnson syndrome is a rare but very serious reaction that usually happens after the body is exposed to a trigger, most often a medicine. The reaction ...

Intravitreal endophthalmitis is a severe, sight-threatening infection inside the eye that happens after a tiny needle is used to place medicine into the ...

Sterile endophthalmitis means that the inside of the eye becomes very inflamed, but there is no living germ causing an infection. The word “endophthalmitis” ...

Stereopsis means “seeing depth with two eyes.” It is the brain’s special skill that lets you feel how far or near things are by comparing the tiny differences ...