What is sympathetic ophthalmia?
Sympathetic ophthalmia (SO) is a rare granulomatous uveitis that develops after a penetrating injury or surgery to one eye, resulting in an autoimmune response that affects both eyes. This condition is defined by inflammation that begins...
Definition of Lens Subluxation
Subluxation of the lens, also known as lens dislocation, is an ocular condition in which the natural lens of the eye is displaced from its original position. This can happen due to weakened or broken zonules,...
Subconjunctival hemorrhage is a common ocular condition defined by the sudden appearance of a bright red or dark patch on the white part of the eye (sclera). This condition occurs when small blood vessels beneath the conjunctiva, the transparent...
Strabismus, also known as "crossed eyes," is a condition in which the eyes do not properly align. One eye can turn inward, outward, upward, or downward, while the other focuses on an object. This misalignment can occur continuously or...
What is Strabismic Amblyopia?
Strabismic amblyopia, also known as "lazy eye," is a vision development disorder in which an eye fails to achieve normal visual acuity, usually due to strabismus, or misalignment of the eyes. When one eye is misaligned,...
Squamous cell carcinoma (SCC) of the eyelid is a malignant tumor that develops from squamous cells, which are flat cells that line the skin's surface. It is the second most common type of eyelid cancer, trailing only basal cell...
Solar retinopathy is an ocular condition caused by direct exposure to intense sunlight or other sources of ultraviolet (UV) radiation, such as during a solar eclipse or prolonged sun exposure. This condition occurs when UV rays damage the retina,...
What is sickle cell retinopathy?
Sickle cell retinopathy is a serious ocular condition that affects people who have sickle cell disease (SCD), a genetic blood disorder defined by the production of abnormal hemoglobin known as hemoglobin S. This condition causes...
Serpiginous choroiditis, also known as geographic choroidopathy, is a rare, chronic, and progressive inflammatory disease of the choroid and retinal pigment epithelium (RPE) of the eye. Serpentine or snake-like lesions spread centrifugally from the optic disc and involve the...
What is secondary glaucoma?
Secondary glaucoma is a type of glaucoma that develops as a result of another eye condition or injury. Secondary glaucoma, as opposed to primary glaucoma, is caused by eye trauma, inflammation, tumors, advanced cataracts, diabetes, or...
What is secondary cataract?
Secondary cataract, also known as posterior capsular opacification (PCO), is a common complication that can develop following cataract surgery. While cataract surgery removes the cloudy lens and replaces it with an artificial intraocular lens (IOL), the...
Definition of Secondary Acquired Lacrimal Duct Obstruction
Secondary acquired lacrimal duct obstruction (SALDO) is a condition in which the tear drainage system of the eye becomes clogged due to an external factor or underlying disease, causing excessive tearing (epiphora) and...
Scleromalacia perforans is a severe, progressive form of scleritis that causes thinning and degeneration of the sclera, the white outer layer of the eye, with no significant inflammation. This condition is frequently associated with autoimmune diseases, specifically rheumatoid arthritis....
What is scleritis?
Scleritis is a severe inflammatory disease of the sclera, the white outer layer of the eye. This condition is characterized by severe pain, redness, and tenderness in the eye, and if not treated properly, it can cause...
Scleral staphyloma is a serious ocular condition marked by an outpouching or bulging of the weakened sclera, the white outer layer of the eye, which is frequently accompanied by thinning and degeneration of the underlying uveal tissue. This condition...
Scleral melanocytosis is a benign ocular condition characterized by abnormal proliferation of melanocytes, or pigment-producing cells, within the sclera, the eye's white outer layer. This results in gray or blue-gray patches on the sclera. The condition is usually congenital,...
Scleral icterus is a medical condition in which the sclera, or white part of the eye, yellows as a result of elevated bilirubin levels in the blood. This yellow discoloration occurs when bilirubin, a byproduct of red blood cell...
Scleral ectasia is a rare, progressive ocular condition that causes the sclera, the eye's white outer layer, to thin and bulge. This condition can cause significant visual impairment and discomfort. The sclera supports and protects the eye, and any...
Sarcoidosis is a multi-system inflammatory disease characterized by the formation of granulomas, or immune cell clusters, in various organs. It can affect any part of the body, but it is most commonly seen in the lungs, lymph nodes, skin,...
What is retinoschisis?
Retinoschisis is an eye condition characterized by the splitting of retinal layers, which causes vision impairment. The term "retinoschisis" comes from Greek, which means "splitting of the retina." This condition can be either congenital (juvenile retinoschisis) or...
Retinopathy of Prematurity (ROP) is a potentially blinding eye disorder that mostly affects premature infants with low birth weights. This condition develops when abnormal blood vessels grow and spread throughout the retina, the light-sensitive tissue that lines the back...
Retinoblastoma is a rare, malignant tumor of the retina that primarily affects young children under the age of five. It develops from retinal cells, which are expected to mature into light-sensing cells. This cancer, which is known to develop...
What is retinitis?
Retinitis is a group of inflammatory diseases that affect the retina, which is the light-sensitive layer of tissue in the back of the eye that converts light into neural signals. These conditions can cause visual impairment and,...
What is retinitis pigmentosa?
Retinitis Pigmentosa (RP) is a group of inherited retinal disorders characterized by progressive degeneration of photoreceptor cells in the retina, which results in vision loss. The retina is a light-sensitive layer of tissue in the back...
What is retinal vein occlusion?
Retinal vein occlusion (RVO) is a common vascular disorder of the retina that causes sudden and severe vision loss. It happens when one of the veins that transport blood away from the retina becomes clogged,...
Retinal telangiectasia, also known as macular telangiectasia (MacTel), is a rare, progressive eye condition characterized by abnormal dilation and twisting of blood vessels in the retina, particularly in the macula, the central part of the retina responsible for sharp,...
What is Retinal Hemangioblastoma?
Retinal hemangioblastoma is a rare, benign vascular tumor of the retina that is frequently associated with von Hippel-Lindau (VHL) disease, a genetic condition that predisposes people to a variety of tumors and cysts throughout their bodies....
Retinal detachment is a serious ocular condition in which the retina, the light-sensitive layer of tissue in the back of the eye, separates from the supporting tissue. If not treated promptly, this separation can cause vision loss. The retina...
What is a Retinal Astrocytic Hamartoma?
Retinal astrocytic hamartoma is a rare, benign ocular tumor that develops from the retina's supporting glial cells (astrocytes). These tumors are commonly associated with genetic conditions such as tuberous sclerosis complex (TSC) and neurofibromatosis...
Retinal artery occlusion (RAO) is a serious ocular condition defined by a sudden blockage of blood flow in one of the arteries that supply the retina, the light-sensitive layer at the back of the eye. This blockage can cause...
