What is anterior uveitis?
Anterior uveitis, also known as iritis, is an inflammation of the uvea, or middle layer of the eye, that primarily affects the iris and anterior chamber. This condition is the most common type of uveitis, accounting...
What is the Anterior Subcapsular Cataract?
Anterior subcapsular cataract (ASC) is a type of cataract that develops in the front of the lens, just below the lens capsule. This type of cataract is distinguished by its location and the opacities...
What is anisometropia?
Anisometropia is an ocular condition that causes a significant difference in refractive power between the two eyes. This disparity causes each eye to focus images at different points, resulting in visual discomfort and difficulties. Differences in myopia...
What is Anisocoria?
Anisocoria is a condition characterized by unequal pupil sizes in the eyes, with one larger or smaller than the other. This difference can be a harmless, normal variation in some people, or it can be a sign...
What is Aniridia?
Aniridia is a rare congenital eye condition characterized by the partial or complete absence of the iris, the colored part of the eye that regulates the amount of light that enters it. This condition affects both eyes...
What is Limbal Stem Cell Deficiency?
Limbal stem cell deficiency (LSCD) is an ocular condition characterized by the absence or dysfunction of limbal stem cells, which are essential for the maintenance and regeneration of the corneal epithelium. The limbus, which...
What are the terms Lenticonus and Lentiglobus?
Lenticonus and lentiglobus are rare congenital lens deformities that alter the shape and clarity of the eye's lens, resulting in visual impairment. Lenticonus is distinguished by a conical protrusion of the lens, whereas...
What is lens-induced uveitis?
Lens-induced uveitis is an ocular condition marked by inflammation of the uvea, the eye's middle layer, caused by lens-related issues. This condition can occur as a result of trauma, cataract formation, or lens dislocation, causing lens...
What is Lens-induced glaucoma?
Lens-induced glaucoma is a type of glaucoma that occurs as a result of changes or abnormalities in the eye's lens. This condition can result from a variety of lens pathologies, such as lens dislocation, cataract formation,...
What causes Leber's Hereditary Optic Neuropathy?
Leber's hereditary optic neuropathy (LHON) is a rare inherited mitochondrial disorder that causes acute or subacute loss of central vision. This condition primarily affects young adults and is caused by mitochondrial DNA mutations that...
What is amblyopia?
Amblyopia, also known as "lazy eye," is a visual development disorder in which one eye does not achieve normal visual acuity, even with prescription glasses or contact lenses. It usually begins in infancy or early childhood as...
What is age-related macular degeneration (AMD)?
Age-related macular degeneration (AMD) is a progressive eye disease that affects the macula, the central portion of the retina responsible for sharp, detailed vision. It is the leading cause of vision loss among people...
What is actinic keratosis?
Actinic keratosis (AK), also known as solar keratosis, is a common skin condition characterized by rough, scaly patches caused by prolonged exposure to ultraviolet (UV) radiation. These lesions primarily affect sun-exposed areas such as the face,...
What is achromatopsia?
Achromatopsia is a rare inherited retinal disorder characterized by a total or partial loss of color vision. Individuals with this condition usually have difficulty distinguishing colors, poor visual acuity, and extreme sensitivity to light (photophobia). Mutations in...
Definition of Acanthamoeba Keratitis
Acanthamoeba keratitis is a rare but serious eye infection caused by a microscopic, free-living amoeba called Acanthamoeba. This organism is common in water sources such as lakes, rivers, and tap water, as well as soil and...
What is Leber's Congenital Amaurosis?
Leber Congenital Amaurosis (LCA) is a rare genetic eye disorder that causes severe vision loss from birth or within the first few months of life. This condition affects the retina, the light-sensitive tissue in the...
What is lattice dystrophy?
Lattice dystrophy is a genetic eye disorder that affects the cornea, the transparent, dome-shaped surface that covers the front of the eye. This condition is defined by the accumulation of abnormal protein fibers, known as amyloid...
What is Latent Nystagmus?
Latent nystagmus is an ocular condition defined by involuntary, rhythmic eye movements that occur only when one eye is covered. This type of nystagmus usually appears in infancy or early childhood and is frequently associated with...
What is lagophthalmos?
Lagophthalmos is an ocular condition that causes the eyelids to remain partially closed. This incomplete closure can expose the cornea and conjunctiva, causing dryness, irritation, and potentially damaging the eye. Lagophthalmos can result from a variety of...
What is a Lacrimal Gland Tumor?
Lacrimal gland tumors are abnormal growths that form in the lacrimal glands, which produce tears. These tumors, whether benign or malignant, can have a significant impact on eye health and vision. Symptoms typically include...
What is a Lacrimal Fistula?
Lacrimal fistulas are abnormal connections between the lacrimal sac and the skin or another epithelial surface. This condition allows tears to drain directly from the lacrimal sac to the skin, avoiding the normal nasolacrimal duct....
What is Lacrimal Gland Dislocation?
Lacrimal gland dislocation occurs when the lacrimal gland, which produces tears, moves out of its normal anatomical position. This dislocation can cause visible swelling, discomfort, and functional issues with tear production and drainage. Trauma, aging,...
What is a Lacrimal Fistula?
Lacrimal fistulas are abnormal connections between the lacrimal sac and the skin or another epithelial surface. This condition allows tears to drain directly from the lacrimal sac to the skin, avoiding the normal nasolacrimal duct....
What is Lacrimal Duct Obstruction?
Lacrimal duct obstruction, also known as nasolacrimal duct obstruction, is a condition that occurs when the tear drainage system of the eye becomes clogged. This blockage prevents tears from draining properly, resulting in watery eyes,...
What is keratoconus?
Keratoconus is a progressive eye disorder in which the cornea, or clear front surface of the eye, thins and bulges outward into a cone-like shape. This abnormal shape prevents light entering the eye from properly focusing on...
What is keratitis?
Keratitis is an inflammation of the cornea, the transparent, dome-shaped surface that covers the front of the eye. This condition can cause pain, redness, and vision problems, and if not treated, it can progress to severe complications,...
What is Juvenile X-Linked Retinoschisis?
Juvenile X-linked retinoschisis (XLRS) is a hereditary retinal disorder that predominantly affects men. The retinal layers split (schisis), resulting in impaired vision. The condition usually manifests in childhood and can cause a variety of visual...
What is Juvenile Open Angle Glaucoma?
Juvenile open-angle glaucoma (JOAG) is a rare but serious eye condition that typically affects people aged three to forty. Unlike primary open-angle glaucoma, which is more common in older adults, JOAG develops earlier and...
What is Juvenile Idiopathic Arthritis-Related Eye Disorder?
Juvenile idiopathic arthritis-related eye disease (JIA-associated uveitis) is an inflammatory condition that affects the eyes of children suffering from juvenile idiopathic arthritis. If not diagnosed and treated promptly, this ocular disease can cause...
What is ischemic optic neuropathy?
Ischemic optic neuropathy (ION) is a condition that causes sudden loss of vision due to decreased blood flow to the optic nerves. This condition can affect one or both eyes and is typically divided into...
