Ophthalmology Knowledge Base

Aberration: A defect in the eye's optical system that causes light rays to not meet exactly at the center of the retina. There are two types: spherical aberration (light passing through the edge of the lens is refracted differently than it is in the center) and chromatic aberration (light of different colors is refracted differently).

Aberrometer: A modern diagnostic tool used for wavefront measurement. It can be used to map all optical defects of the eye before laser eye surgery.

Accommodation: The eye's ability to focus at different distances by changing the shape of the lens. This ability decreases with age.

Suitability test: A detailed ophthalmological examination that determines whether the patient is suitable for vision correction surgery (based on corneal thickness, diopters, tear film, etc.).

Astigmatism (cylindricality): A refractive error that occurs when the cornea of ​​the eye is not perfectly spherical, but rather feels as if it has been slightly squeezed from one direction. Light rays do not meet at the same point on the retina. Typical symptoms include blurred vision at all distances and frequent squinting.

Avastin injection: Originally an anti-tumor agent, but in ophthalmological applications it also inhibits abnormal neovascularization in the retina.

Choroid (blood vessel membrane): The back part of the middle layer of the eye, which is richly vascularized and responsible for nourishing the retina.

Contoura Vision: A premium, topography-guided laser vision correction procedure that addresses not only the diopter but also the unique irregularities of the cornea, providing a more personalized and precise result.

Cornea: See cornea.

Diabetes mellitus: A metabolic disease in which the body cannot properly regulate blood sugar levels. In the long term, it can damage blood vessels, nerves, and various parts of the eye.

Cylindricality: See astigmatism.

Diabetic retinopathy: A complication of diabetes in which the blood vessels in the retina are damaged, causing bleeding, swelling, and scarring, ultimately causing vision loss.

Diopter: A unit of measurement for the refractive power of spectacle lenses and the eye. One diopter means that the lens focuses at a distance of 1 meter. The higher the diopter number, the stronger the refractive error.

EDOF (Extended Depth of Focus) lens: A special premium artificial lens that provides clear vision at far and intermediate distances (e.g. computer, dashboard). The advantage is that it causes less halos and glare than multifocal lenses.

Night vision: After lens surgery, an important aspect is how clearly the patient sees in the dark while driving. Modern premium lenses have less halos and glare, making night driving safer.

Anterior chamber: The fluid-filled cavity between the cornea and the iris. It contains the aqueous humor, the amount of which determines the pressure inside the eye.

Emmetropia: The condition of a healthy eye without refractive error, when light rays meet exactly at the center of the retina.

Neovascularization: A pathological process in which new, fragile, and irregular blood vessels develop in the eye (e.g., in the macula). These blood vessels often leak or bleed, which can lead to vision loss. It is characteristic of wet macular degeneration, but can also occur in other eye diseases.

Excimer laser: A special type of laser used in laser eye surgery to precisely modify the shape of the cornea.

FDA approval: A certificate issued by the US Food and Drug Administration (FDA) that proves that laser technology is safe and effective.

FEMTO: A type of laser eye surgery performed using a femtosecond laser, also known as dual-laser treatment. It offers maximum comfort and safety.

Flashes of light: Flashes of light in the visual field, which can be caused by a pulling or detachment of the retina.

Refraction: Refers to the process by which light changes direction as it passes through different optical media (cornea, lens). The refractive power of the eye determines the acuity of vision.

Glaucoma: A group of eye diseases that damage the optic nerve, the most common cause of which is increased intraocular pressure. It develops gradually, usually painlessly, initially causing a narrowing of peripheral vision. Without treatment, it can cause permanent vision loss and, ultimately, blindness. Treatment options include eye drops that lower intraocular pressure, laser procedures, and surgery. Regular eye examinations are essential to slow the progression of the disease.

Gonioscopy: An eye test that examines the anterior chamber with a special lens. It is important in the diagnosis of glaucoma.

Three-mirror examination: An examination performed with a special contact lens that allows examination of the retina's periphery and the antecubital fossa.

Hypermetropia (farsightedness): A refractive error where the eyeball is shorter than normal, causing light rays to meet behind the retina. Near objects appear blurry, while distant objects are often sharp.

ICL (Implantable Collamer Lens): An implantable artificial lens that provides an alternative for those who are not suitable for laser eye surgery.

Intravitreal injection: An injection into the vitreous of the eye, which delivers a drug (e.g. anti-VEGF) directly near the retina.

Iris: See iris.

Keratoconus: A disease characterized by progressive thinning of the cornea, in which the normal hemispherical shape becomes conical. It causes increasing astigmatism and impaired vision, especially in the dark.

Keratometry: A test to measure the curvature of the cornea, which is essential for planning laser eye surgery.

Control test: A series of mandatory medical check-ups after surgery to ensure monitoring of recovery.

Corneography: See topography.

Distance between: The dashboard of a computer, tablet or car is typically at an intermediate distance. Premium (EDOF, trifocal) lenses correct this as well, eliminating the need for separate glasses.

Narrowing of the field of vision: Loss of peripheral vision is a characteristic symptom of glaucoma, diabetic retinopathy, or other retinal diseases.

LASIK: A “Laser Assisted in Situ Keratomileusis” rövidítése. Lebenyképzéses lézeres eljárás, amelyben egy védőlebenyt képeznek, majd a szaruhártya középső rétegében végzik el a korrekciót.

FOREST: A “Laser Assisted Sub-Epithelial Keratomileusis” rövidítése. Felszíni lézeres eljárás, amely a szaruhártya felszínén dolgozik.

Lens (eye lens): A transparent, flexible structure behind the pupil that can change its shape and thus project a sharp image of objects at different distances onto the retina.

Lucentis injection: An anti-VEGF drug administered as an intravitreal injection for the treatment of macular degeneration and diabetic retinopathy.

Macular degeneration (AMD): A disease affecting the central part of the retina, the macula (yellow spot), which leads to a gradual deterioration of sharp, central vision. There are two main types: the dry form, which develops slowly due to cell death, and the wet form, which is associated with rapid vision loss due to abnormal new blood vessels. It is more common in people over 60 years of age, and risk factors include smoking, genetic predisposition and high blood pressure. Its treatment depends on the type: vitamins, antioxidants, or in the case of the wet form, special injection therapy (anti-VEGF).

Monofocal intraocular lens: An artificial lens that provides sharp vision at a specific distance (usually distance). Glasses may still be needed for reading or close-up work.

Multifocal intraocular lens: An artificial lens that provides sharp vision at multiple distances (near, intermediate, and far). In many cases, it eliminates the need for glasses for everyday activities.

Myopia: See myopia.

OCT (optical coherence tomography): An imaging test that provides a cross-sectional view of the layers of the retina, similar to an ultrasound, but using light waves.

Reading glasses problem: A condition that often occurs in people over the age of 45, when reading glasses are required due to deterioration of near focus. Multifocal or trifocal intraocular lenses can cause this.

Pachymetria: A test to measure the thickness of the cornea. It is essential for the safe performance of laser eye surgery.

Phacoemulsification: An ultrasonic technique in which the natural lens of the eye is cut up and removed, then replaced with an artificial lens. It is the basis of most modern cataract and lens surgeries.

Presbyopia (old-sightedness): A natural age-related change that occurs after the age of 40. Difficulty seeing close objects occurs due to a decrease in the elasticity of the lens.

PRK Surgery: A “PhotoRefractive Keratectomy” rövidítése. A legrégebbi, felszíni lézeres eljárás, amely közvetlenül a szaruhártya felszínén végzi a korrekciót.

Pupil (eyeball): A round opening in the center of the iris that controls the amount of light entering the eye, similar to the aperture of a camera.

Retina: The innermost layer of the eye, containing light-sensitive cells and where the process of vision begins. This is where the image is formed and transmitted to the brain.

Myopia: A refractive error where the eyeball is longer than normal or the curvature of the cornea is too great. Distant objects appear blurry, while nearby objects appear sharp.

Cornea: The transparent, anterior protective covering of the eye, which accounts for most of the eye's refractive power. It is approximately 0.5 mm thick and has a refractive power of ~43 diopters.

Ophthalmic ultrasound: An examination method that uses ultrasound to image the internal structures of the eye, even if the fundus is not visible (e.g. due to bleeding).

Eye pain: A sensation of pain originating from different layers of the eye, which may be due to inflammation, injury, or increased intraocular pressure.

Fundus examination: An ophthalmological examination performed after pupil dilation, which allows direct observation of the condition of the retina and blood vessels.

Glasses-free: The ability for a patient to see clearly without glasses or contact lenses. With premium contact lenses, it is often possible to see at all distances.

Iris: Part of the middle layer of the eye that determines the color of the eye through its pigment content. It contains the muscles that control the pupil.

Foresight: A refractive error where the eyeball is shorter than normal, causing light rays to meet behind the retina. Near objects appear blurry, while distant objects are often sharp.

Topography: A test to map the surface curvature of the cornea in detail. It creates a three-dimensional map of the cornea.

Touch-free treatment: A non-contact surface laser procedure where the removal of the corneal epithelium is also performed by a laser, resulting in faster and more even healing.

Toric intraocular lens: A special artificial lens that also corrects astigmatism. Available in mono-, multi- and trifocal versions.

Floating shadows: Small moving spots or threads in the field of vision caused by changes in the vitreous. Mostly harmless, but can also be a sign of retinal detachment.

Glass body: A transparent, jelly-like substance located behind the lens of the eye, filling the back of the eye and providing internal support to the eyeball.

Blindness: Severe or complete loss of vision. One of the biggest fears of patients before eye surgery, but an extremely rare risk with modern procedures.

Glaucoma: see Glaucoma