Page 70 - The UK Guide to Laser Eye Surgery
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 70 Glossary
Glossary A
Ablation
The removal of organic material from the cornea by an excimer laser in laser eye surgery.
Accommodation
The automatic adjustment of the eye for seeing at different distances, usually via changes in the convexity of the lens inside the eye.
Acuity
The sharpness or clarity of vision. The most common measure of visual acuity is the Snellen acuity chart used by optometrists and ophthalmologists. Normal visual acuity is known as ‘20/20 vision’.
Amblyopia
Amblyopia, also known a ‘lazy eye’, is a condition where the vision in one is not fully developed, often due to lack of use in early childhood.
Artemis / Insight
A trade name for a Very high-frequency (VHF) ultrasound manufactured by ArcScan Inc, which measures corneal thickness to the accuracy of 1 micron. It produces a
3D image, which means it can detect the overall depth and thinnest point of the cornea with great accuracy.
Astigmatism
A condition in which the surface of the cornea is not spherical, but shaped like a rugby ball. An astigmatic cornea focuses incoming images on two separate points in the eye, creating a distorted image. The second number on your glasses prescription refers to your degree of astigmatism.
B
Bifocals
Corrective lenses that have two powers of correction. Typically, most of the
lens is used for distance vision while a smaller area is for near vision. Bifocals and varifocals are normally prescribed for individuals with presbyopia (ageing eyes).
Binocular vision
The blending of images seen individually by each eye into a single image.
C
Cataract
A condition caused by the clouding of the natural lens inside the eye.
Clear Lens Exchange (CLE)
A surgical procedure, similar to cataract surgery, in which a surgeon removes the crystalline lens from the eye and replaces it with a clear plastic intraocular lens (IOL).
Contrast sensitivity
The ability to perceive differences between an object and its background, i.e. the ability to distinguish a grey object on a grey background.
Cornea
The transparent covering at the front of the eye. Most laser eye surgery procedures work by changing the curvature of the cornea.
Corrected Distance Visual Acuity (CDVA)
A measure of a patient’s best possible visual clarity whilst wearing corrective lenses, such as glasses or contact lenses.
Crystalline lens
See ‘Lens’
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