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Basic Vision and Vision Problems

Glossary of terms related to basic vision and vision problems.

Accommodation
The act of focusing that occurs when the ciliary muscle contracts. When it contracts, the eyes power increases, allowing it to focus on smaller ojbects nearby.

Accommodative spasm
An accommodative spasm is a condition that causes the eye muscle to accommodate or focus constantly and automatically.

Amblyopia
Amblyopia is commonly known as "lazy eye." The eye appears healthy, but visual information is not transmitted or recognized properly through the visual and neural systems.

Anisocoria
Learn the definition of anisocoria.

Anti-Reflective Coating
Learn the definition of anti-reflective coating.

Arcus Senilis
Learn the definition of arcus senilis.

Astigmatism
A refractive error in which light rays fail to come to a single focus on the retina because of differing amounts of refraction in the various meridians of the eye.

Bifocal
Bifocals are lenses that have two focal points, one for near vision and one for distance.

Binocular Vision
Binocular vision is the ability to use both eyes as a team.

Bitemporal Heminopsia
Learn the definition of bitemporal heminopsia.

Depth Perception
Learn the definition of depth perception.

Emmetropia
Learn the definition of emmetropia.

Eye Doctor
Learn the definition of eye doctor.

Hyperopia
Hyperopia is better known as farsightedness. Patients with farsightedness generally see well at a distance, but have difficulty seeing clearly at a close range.

IntraLASIK
IntraLASIK is a bladeless form of LASIK eye surgery.

LASIK
LASIK is the most commonly performed type of laser surgery to correct vision problems.

Lenticular astigmatism
Astigmatism due to a defect in the curvature, position, or index of refraction of the lens.

Myopia
A refractive error commonly known as nearsightedness. In myopia, the eyeball is too long in relation to its focusing power. This causes difficulty in seeing distant objects.

Peripheral Vision
Peripheral vision is the field of view that surrounds the central portion of the vision field.

Phoria
Learn the definition of phoria.

Pinhole Glasses
Pinhole glasses are eyeglasses with special lenses consisting of a series of tiny "pinholes."

Presbyopia
A condition common after age 40 in which a gradual lessening of the eye's power of accommodation causes difficulty in seeing near objects. Presbyopia is usually the cause of why people need reading glasses or bifocals after the age of 40.

RGP Contact Lenses
Rigid Gas Permeable (RGP) contact lenses are made of hard plastic that gives crisp, clear vision and corrects most vision problems.

Silicone Hydrogel Contact Lenses
Learn the definition of silicone hydrogel contact lenses.

Tunnel Vision
Learn the definition of tunnel vision.

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