Stevens-Johnson syndrome is a rare, severe inflammatory reaction that affects the skin and mucous membranes. It is most often discussed as a medication- or infection-triggered condition that can become a medical emergency. In eye care, it matters because it can injure the conjunctiva and cornea and threaten vision. The term is commonly used in hospital medicine, dermatology, and ophthalmology to describe this specific syndrome and its complications.

conjunctival scarring means fibrous healing changes in the conjunctiva, the thin, clear tissue covering the white of the eye and lining the eyelids. It can follow inflammation, infection, injury, chemical exposure, autoimmune disease, or eye surgery. Clinicians use the presence and pattern of conjunctival scarring as an important sign when evaluating “ocular surface disease” (conditions affecting the eye’s surface). It may be mild and focal or severe enough to change eyelid shape, tear function, and vision.

symblepharon is an abnormal adhesion between the eyelid lining (palpebral conjunctiva) and the surface lining of the eye (bulbar conjunctiva). It forms when conjunctival tissues heal together after injury or inflammation and create scar bands. The term is used in eye exams, surgical planning, and ocular surface disease documentation. It can affect comfort, eye movement, tear function, and sometimes vision depending on severity.

corneal perforation means a full-thickness break in the cornea, the clear “window” at the front of the eye. It creates an abnormal opening between the outside surface and the inside of the eye. Clinicians use the term when describing urgent corneal disease or eye injury. It is commonly discussed in emergency eye care, cornea clinics, and eye surgery settings.

A Descemetocele is a severe corneal ulcer in which the cornea has thinned down to Descemet’s membrane. It often appears as a clear, dome-like bulge at the base of a deep corneal ulcer. It is considered an ophthalmic emergency because it can progress to a corneal perforation. The term is most commonly used in cornea clinics, emergency eye care, and surgical decision-making.

corneal scarring is a loss of normal corneal clarity caused by healed injury or inflammation in the cornea. In plain terms, it is a “mark” in the eye’s clear window that can scatter light and affect vision. It is commonly discussed in eye exams when people have blurred vision, glare, or a history of infection or trauma. Clinicians document corneal scarring to guide diagnosis, monitoring, and treatment planning.

corneal neovascularization means new blood vessels growing into the cornea. The cornea is normally clear and does not contain blood vessels. This finding is commonly discussed in eye exams, contact lens care, and corneal disease management. Clinicians use the term to describe a sign of stress, inflammation, low oxygen, or injury affecting the cornea.

limbal stem cell deficiency is a disorder of the eye surface where the cornea loses enough stem cells to renew its outer lining. It can lead to chronic irritation, blurred vision, and recurrent breakdown of the corneal surface. Clinicians use the diagnosis to explain persistent “non-healing” corneal problems and to plan surface-focused treatment. It is most often discussed in cornea clinics, dry eye/ocular surface care, and ocular surface reconstruction.

pinguecula is a common, usually benign growth on the conjunctiva, the clear tissue covering the white of the eye. It often appears as a small yellowish, slightly raised spot near the edge of the cornea. The term pinguecula is used in eye clinics to describe a typical ocular surface change related to irritation and environmental exposure.

pterygium is a common growth of conjunctival tissue that extends onto the cornea. It is often described as a “wing-shaped” fibrovascular (fibrous and blood vessel–rich) lesion. It most commonly appears on the nasal (nose-side) white of the eye and grows toward the pupil. The term is used in eye clinics to describe a specific ocular surface condition that may be monitored or treated.

bullous keratopathy is a condition where the cornea (the clear front window of the eye) becomes swollen and develops fluid-filled blisters. It usually happens when the cornea’s inner “pump” layer (the endothelium) is not working well. People may notice blurred vision, glare, and episodes of pain when blisters break. The term is commonly used in eye clinics to describe corneal edema with epithelial bullae and to guide treatment planning.

map-dot-fingerprint dystrophy is a common corneal surface condition that affects the clear front window of the eye. It is also known in clinics as epithelial basement membrane dystrophy (EBMD). It can cause fluctuating vision and episodes of painful “corneal erosions” in some people. The term is commonly used in eye exams, contact lens care, and pre-surgical screening.

epithelial basement membrane dystrophy is a common corneal surface condition that affects how the outermost corneal cells attach and heal. It is sometimes called “map-dot-fingerprint dystrophy” because of its typical patterns on exam. It can cause fluctuating vision, irritation, or episodes of recurrent corneal erosion (sudden pain from surface breakdown). It is most commonly discussed in eye clinics during corneal evaluations, dry eye workups, and pre-surgical screening.

macular dystrophy is a group of mostly inherited (genetic) eye conditions that affect the macula. The macula is the central part of the retina responsible for sharp, detailed vision. These conditions are commonly discussed in retina clinics and in genetic eye disease care. The term is also used in education and research to describe macula-centered retinal degeneration.

granular dystrophy is an inherited condition that affects the clear front window of the eye called the cornea. It causes small, crumb-like (“granular”) deposits to build up within the corneal tissue over time. The term is commonly used in eye clinics to describe a specific pattern of corneal clouding seen on examination. It matters because these deposits can scatter light and gradually affect vision and comfort.

lattice dystrophy is a corneal dystrophy, meaning an inherited (or sometimes acquired) condition that affects the clear front window of the eye (the cornea). It is named for “lattice-like” branching lines that can be seen in the cornea on an eye exam. It is most commonly discussed in cornea clinics, comprehensive eye care, and ophthalmology training as a cause of corneal clouding and recurrent corneal erosions. It can affect vision and comfort over time, with severity varying by person and subtype.

Fuchs endothelial dystrophy is a progressive corneal disease that affects the innermost layer of the cornea. It reduces the cornea’s ability to stay clear by impairing fluid control inside the corneal tissue. People often notice blurry or hazy vision that can be worse on waking and improve later in the day. The term is commonly used in eye exams, cataract surgery planning, and corneal specialty care.

corneal dystrophy is a group of usually inherited conditions that affect the cornea, the clear front window of the eye. It involves abnormal changes in one or more corneal layers that can reduce clarity or alter the corneal surface. The term is commonly used in eye clinics to describe specific, patterned corneal diseases that are not caused by infection or injury. Some forms mainly cause fluctuating vision, while others cause recurrent pain or progressive corneal swelling.

A corneal foreign body is material that becomes stuck on or in the cornea, the clear front “window” of the eye. It often happens during activities like grinding, drilling, sanding, yard work, or contact lens wear. Clinicians commonly evaluate it in emergency departments, urgent care, and eye clinics. It is discussed as both a diagnosis (what happened) and a clinical problem that may require removal and monitoring.

recurrent corneal erosion is a condition where the cornea’s surface layer repeatedly breaks down. It often causes sudden eye pain, tearing, and light sensitivity, commonly on waking. In plain terms, it is like a “re-opening” of a prior scratch on the eye’s clear window. It is commonly discussed in eye clinics when evaluating repeated corneal abrasions or morning pain.