Eye Care Glossary

Myopia: A common refractive error where close objects can be seen clearly, but distant objects appear blurry. Myopia occurs when the eyeball is too long or the cornea is too curved, causing light rays to focus in front of the retina instead of directly on it.

Hyperopia: Also known as farsightedness, hyperopia is a refractive error where distant objects can be seen more clearly than close objects. This occurs when the eyeball is too short or the cornea is too flat, causing light rays to focus behind the retina instead of on it.

Astigmatism: A refractive error that occurs when the cornea or lens of the eye is irregularly shaped, causing blurry or distorted vision at all distances. Astigmatism can coexist with myopia or hyperopia.

Presbyopia: An age-related condition where the lens of the eye loses its ability to focus on close objects, making near vision blurry. This typically occurs in people over 40 years old and is often corrected with reading glasses or multifocal lenses.

Cataract: A clouding of the eye’s natural lens that can cause vision to become blurry or hazy. Cataracts are most commonly age-related but can also be caused by injury, disease, or genetic factors. Surgery is often necessary to remove cataracts and restore clear vision.

Glaucoma: A group of eye conditions that damage the optic nerve, often due to increased pressure within the eye. Glaucoma can lead to vision loss or blindness if left untreated, but early detection and treatment can help preserve vision.

Macular Degeneration: A progressive eye disease that affects the macula, the central part of the retina responsible for sharp, central vision. Age-related macular degeneration is the most common form and can lead to a loss of central vision over time.

Diabetic Retinopathy: A complication of diabetes that affects the blood vessels in the retina, leading to vision loss or blindness if left untreated. Diabetic retinopathy can cause symptoms such as blurred vision, floaters, and difficulty seeing at night.

Retinal Detachment: A serious eye emergency where the retina pulls away from the underlying layers of the eye, disrupting blood supply and causing vision loss. Symptoms of retinal detachment include flashes of light, floaters, and a curtain-like shadow over the field of vision.

Dry Eye Syndrome: A common condition where the eyes are unable to produce enough tears or produce poor-quality tears, leading to symptoms such as dryness, irritation, and blurred vision. Dry eye syndrome can be caused by factors such as age, hormonal changes, medications, or environmental factors.

Refractive Surgery: A surgical procedure that corrects refractive errors such as myopia, hyperopia, and astigmatism by reshaping the cornea to improve vision. Common forms of refractive surgery include LASIK, PRK, and SMILE.

Amblyopia: Also known as lazy eye, amblyopia is a condition where one eye has reduced vision that cannot be corrected with glasses or contact lenses. This typically occurs in childhood and can lead to permanent vision loss if left untreated.

Pterygium: A growth of pink, fleshy tissue on the white part of the eye (sclera) that can extend onto the cornea and affect vision. Pterygium is often caused by exposure to UV light, wind, or dust, and may require surgical removal if it affects vision.

Strabismus: A misalignment of the eyes where one eye may turn in, out, up, or down, causing double vision or reduced depth perception. Strabismus can be present from birth or develop later in life and may be treated with vision therapy, glasses, or surgery.

Conjunctivitis: Commonly known as pink eye, conjunctivitis is an inflammation of the outermost layer of the eye and inner surface of the eyelids. It can be caused by viruses, bacteria, allergens, or irritants and may result in redness, itching, and discharge from the eyes.

Keratoconus: A progressive eye disease where the cornea thins and bulges into a cone shape, causing distorted vision and sensitivity to light. Keratoconus typically begins in adolescence or early adulthood and may be managed with specialized contact lenses or surgery.

Retinitis Pigmentosa: A group of inherited eye diseases that cause gradual degeneration of the retina, leading to night blindness and tunnel vision. Retinitis pigmentosa can progress to complete blindness, but treatments may help slow the progression of the disease.

Uveitis: An inflammation of the uvea, the middle layer of the eye that includes the iris, ciliary body, and choroid. Uveitis can be caused by infections, autoimmune conditions, or trauma, and may result in eye pain, redness, blurred vision, and light sensitivity.

Keratitis: An inflammation of the cornea often caused by infection, injury, or underlying conditions such as dry eye or contact lens misuse. Symptoms of keratitis may include eye pain, redness, blurred vision, and sensitivity to light, and prompt treatment is essential to prevent complications.

Eye Allergy: An allergic reaction affecting the eyes due to triggers such as pollen, dust mites, pet dander, or mold. Symptoms of eye allergy may include redness, itching, watering, and swelling of the eyelids, and management may involve avoiding triggers and using antihistamines or eye drops.

Optic Neuritis: An inflammation of the optic nerve, which transmits visual information from the eye to the brain. Optic neuritis can cause sudden vision loss, eye pain with movement, and changes in color perception, and may be associated with conditions such as multiple sclerosis.

Ophthalmologist: A medical doctor specializing in the diagnosis and treatment of eye diseases and disorders. Ophthalmologists are trained to perform eye surgeries, prescribe medications, and provide comprehensive eye care for patients of all ages.

Optometrist: A healthcare professional trained to perform eye exams, prescribe corrective lenses, and diagnose and manage common eye conditions. Optometrists are not medical doctors but can provide primary eye care and refer patients to ophthalmologists for specialized treatment.

Orthoptist: A healthcare professional who specializes in the diagnosis and non-surgical management of eye movement disorders and binocular vision problems. Orthoptists work closely with ophthalmologists to assess and treat conditions such as strabismus and amblyopia.

Visual Field Test: A diagnostic test that assesses the full extent of a person’s peripheral vision and sensitivity to light. Visual field testing is used to detect abnormalities in the visual field caused by conditions such as glaucoma, retinal detachment, or neurological disorders.

Tonometry: A diagnostic test that measures the pressure inside the eye, known as intraocular pressure. Tonometry is commonly used to screen for glaucoma, a condition that can cause damage to the optic nerve if left untreated.

Slit Lamp Exam: A detailed examination of the structures of the eye using a specialized microscope called a slit lamp. This allows eye care professionals to visualize the cornea, iris, lens, and other parts of the eye in high magnification and under intense illumination.

Fundus Photography: A non-invasive imaging technique that captures detailed photographs of the back of the eye, including the retina, optic nerve, and blood vessels. Fundus photography is used to document and monitor eye conditions such as diabetic retinopathy, macular degeneration, and glaucoma.

Fluorescein Angiography: A diagnostic procedure that uses a fluorescent dye to visualize the blood flow in the retina and choroid of the eye. Fluorescein angiography helps eye care professionals identify abnormalities in the blood vessels, such as leaks or blockages, that may indicate conditions like macular degeneration or diabetic retinopathy.

Optical Coherence Tomography (OCT): An imaging technique that captures high-resolution, cross-sectional images of the retina to assess its thickness and structure. OCT is used to detect and monitor conditions such as macular edema, glaucoma, and age-related macular degeneration, allowing for early intervention and treatment.

Visual Acuity: A measure of the clarity or sharpness of vision, typically assessed using a Snellen chart or other visual acuity testing methods. Visual acuity is expressed as a fraction, with 20/20 vision considered normal or standard vision.

Ocular Surface Disease: A group of conditions that affect the surface of the eye, including the cornea, conjunctiva, and tear film. Ocular surface disease can cause symptoms such as dryness, irritation, redness, and blurred vision, and may be managed with artificial tears, medications, or lifestyle modifications.

Corneal Ulcer: An open sore or lesion on the surface of the cornea, often caused by infection, injury, or underlying conditions such as dry eye or contact lens misuse. Corneal ulcers can lead to pain, redness, discharge, and vision loss, and require prompt treatment to prevent complications.

Oculoplastics: A subspecialty of ophthalmology that focuses on the diagnosis and treatment of disorders affecting the eyelids, orbit (eye socket), tear ducts, and facial bones around the eyes. Oculoplastic surgeons perform procedures to correct eyelid malpositions, remove tumors, and restore function and aesthetics to the eye area.

Dacryocystitis: An infection or inflammation of the lacrimal sac, which is responsible for draining tears from the eyes into the nose. Dacryocystitis can cause pain, swelling, and tenderness around the inner corner of the eye, along with tearing, discharge, and blurred vision.

Visual Rehabilitation: A comprehensive approach to improving visual function and quality of life for individuals with visual impairments or low vision. Visual rehabilitation may involve vision therapy, low vision aids, adaptive technology, and lifestyle modifications to maximize residual vision and independence.

Ocular Melanoma: A rare but serious form of cancer that develops in the pigment-producing cells of the eye, most commonly in the uvea (choroid, iris, or ciliary body). Ocular melanoma can cause changes in vision, eye pain, and a visible dark spot on the iris, and may require treatment such as radiation therapy or surgery.

Retinopathy of Prematurity: A potentially blinding eye disorder that affects premature infants with low birth weight, in which abnormal blood vessels grow in the retina. Retinopathy of prematurity can lead to vision loss or retinal detachment if left untreated, and may require laser therapy or surgery to prevent complications.

Scleral Lens: A scleral lens is a type of contact lens that is larger in diameter and rests on the sclera (white part of the eye) rather than the cornea (clear front part of the eye). Scleral lenses are known for their comfort and ability to provide clear vision for those with various eye conditions.

Cornea: The cornea is the clear, dome-shaped surface that covers the front part of the eye. When wearing scleral lenses, the cornea is not in direct contact with the lens, which can help improve comfort and reduce the risk of damage to the corneal tissue.

Sclera: The sclera is the tough, protective outer layer of the eye that covers most of the eye’s surface. Scleral lenses rest on the sclera, providing a more stable and comfortable fit compared to traditional contact lenses that rest on the cornea.

Gas Permeable: Gas permeable lenses are made of a rigid, breathable material that allows oxygen to pass through to the cornea. Scleral lenses are a type of gas permeable lens, which helps maintain the health of the eye while providing clear vision and comfort.

Vault: Vault refers to the space between the back surface of a scleral lens and the front surface of the cornea. Having an appropriate vault is important to prevent the lens from rubbing on the cornea, which can cause discomfort and damage to the eye.

Fitting: Fitting refers to the process of determining the appropriate size and shape of a scleral lens for a specific individual’s eye. A proper fitting ensures that the lens rests comfortably on the sclera and provides clear vision without causing any discomfort or complications.

RGP Lens: Rigid gas permeable (RGP) lenses are a type of contact lens made of a rigid material that allows oxygen to pass through to the cornea. Scleral lenses are a type of RGP lens, providing clear vision and comfort while maintaining the health of the eye.

Topography: Topography refers to the mapping of the curvature of the cornea’s surface. In the context of scleral lenses, corneal topography is used to assess the shape and irregularities of the cornea to ensure an accurate fit for the lenses. By analyzing the corneal topography, eye care professionals can customize scleral lenses for individual patients to provide optimal comfort and vision correction.

Profilometry: Profilometry is a method used to measure the surface topography of an object with high precision. In the field of scleral lenses, profilometry is often employed to assess the fit and design of the lenses on the eye. By utilizing profilometry, eye care professionals can evaluate the alignment and vaulting of scleral lenses to ensure they provide a comfortable and effective fit for the patient.