Alcon® AcrySof® ReSTOR® IOL Cataract Surgery Glossary
Accommodation: The ability of the eye's lens to change shape to focus on objects at various distances.
Anesthesia: Medication that eliminates or reduces pain for surgical procedures. Local or regional anesthesia numbs only a certain area.
Apodization: The gradual reduction or blending of the diffractive step heights. The application of apodization to intraocular lenses is a patented process by Alcon and can only be found in the AcrySof® ReSTOR® IOL.
Astigmatism: A vision problem that results in blurred distance and/or near vision. Light rays entering the eye are bent unequally, which prevents the formation of a sharp point of focus on the retina. This creates a blurring of parts of objects you see.
Cataract: A "clouding" of the lens in your eye. As light passes through the cataractous lens, it is diffused or scattered. The result is blurred or defocused vision.
Ciliary body: An eye muscle that controls the shape of the lens to enable the eye to quickly change focus to see objects at near, intermediate and far distances.
Contrast sensitivity: The ability of the eye to differentiate between an object and its background.
Cornea: Clear front surface of the eye that covers the iris and pupil. The cornea provides most of an eye's optical power.
Crystalline lens: Structure inside the eye that help to bring rays of light to a focus on the retina.
Diffraction: The spreading of light. Occurs when light passes through discontinuities (i.e. steps or edges). In an optical system, light can be diffracted to form multiple focal points or images.
Diopter: A unit of measurement for myopia, hyperopia and astigmatism that usually falls within a scale of +14 to -14. A positive number indicates hyperopia and a negative number indicates myopia.
Distance vision: Refers to focal points that are typically 7 feet or further from your eyes. Items that typically fall within the distance range of vision are billboards, street signs, and movie screens.
Halos: A circular flare or hazy ring that may appear around a headlight or other lighted object.
Intermediate vision: Refers to focal points that are typically between 16 inches and 7 feet away from your eyes. Items that typically fall within the intermediate range of vision are computer screens and car dashboards.
Intraocular lens (IOL): An artificial lens that is implanted in the eye to replace the eye's clouded crystalline lens during cataract surgery.
Iris: The colored part of the eye surrounding the pupil which controls the amount of light that enters the eye.
Lens: Structure inside the eye that help to bring rays of light to a focus on the retina. Also known as the human crystalline lens.
Lens haptics: Two arms on the IOL that help keep the lens in place and centered in the eye.
Lens optic: The round central portion of the IOL that serves as the corrective lens.
Monofocal IOL: An intraocular lens that provides patients with only one focal point. Most commonly, these lenses correct only for distance vision.
Monovision: An approach to vision correction that intentionally corrects one eye for distance vision and the other for close vision. This can be done with glasses, contact lenses, or various surgical procedures.
Multifocal IOL: An intraocular lens that provides patients with multiple focal points, correcting vision at a range of distances.
Near vision: Refers to focal points that are typically 16 inches or closer to your eyes. This is also known as "reading vision." Items that typically fall within the near range of vision are books, newspapers, and medicine bottles.
Phacoemulsification: Also called "phaco," this cataract surgery procedure involves using a device with a vibrating, ultrasonic tip to gently break up the cataract and remove it from the eye.
Presbyopia: An eye condition commonly due to aging and a stiffening of the lens, which results in an eye that can no longer accommodate for near or "reading" vision. The individual is no longer able to read clearly and typically requires reading glasses.
Refraction: Redirection of light rays as they pass through the lens.
Retina: The transmitter located at the back of your eye that sends the images to your brain.
Visual acuity: The assessment of the eye's ability to distinguish object details and shape, using the smallest identifiable object that can be seen at a specified distance (usually 20 feet for distance or 16 inches for near).
Visual disturbances: Visual phenomena such as halos or glare that result from optical conditions.
