Page 73 - The UK Guide to Laser Eye Surgery
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 Glossary
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Laser assisted sub-epithelium keratomileusis (LASEK)
A surgical procedure to reshape the cornea by detaching the epithelium with an alcohol solution that softens it and allows it to be rolled back into a flap. After excimer ablation to correct the vision, the flap of epithelium is repositioned over the cornea.
Laser Blended Vision
A laser eye surgery technique for the correction of presbyopia, in which one
eye is treated to view objects mainly at distance, but a little up close and the other is treated to view objects mainly up close, but a little at distance. The brain combines the images and enables the individual to clearly at all distance.
Lens (also called crystalline lens)
The natural lens of the eye is located behind the iris. It helps rays of light to focus on the retina. The lens is transparent, but with age, it can become cloudy (this
is known as a cataract). The lens has the ability to ‘zoom’ its focus from distance to near; however, this reduces with age (this is known as presbyopia).
Long-sightedness
See ‘Hyperopia’
Micron (μm)
A unit of length equal to one-millionth of a metre.
Microkeratome
A surgical device for creating a flap of corneal tissue, used in older forms of LASIK. Most modern laser eye surgeons now use a femtosecond laser to create corneal flaps, instead of a microkeratome.
Monovision
A technique using contact lenses (or older laser systems) to overcome the effects of presbyopia by correcting one eye for near vision and the other for distance vision
– not to be confused with Laser Blended Vision, which is a more sophisticated procedure.
Myopia
Also known as near-sightedness or short- sightedness. Myopia occurs when the eyeball is too deep from front to back
or the eye’s focusing mechanism is too strong. This causes light rays to be focused in front of, rather than on, the retina. People with myopia have difficulty seeing distant objects.
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Near-sightedness
See ‘Myopia’.
Off-centred ablation
See ‘Decentration’.
Ophthalmic
To do with the eye.
Ophthalmologist
A medical doctor who specialises in the diagnosis and medical or surgical treatment of eye diseases. Ophthalmologists have medical degrees and further specialist training. Ophthalmologists are usually trained as surgeons, but some choose not to perform surgery and work as medical ophthalmologists. An ophthalmologist may also prescribe glasses and contact lenses.
Optic nerve
The optic nerve is a bundle of nerve fibres, about the diameter of pencil, which passes through the back of the eyeball and connects the retina to the brain. The optic nerve carries visual messages from the photoreceptors of the retina to the brain.
Optical zone
The area of the eye through which light passes to the retina. To reach the retina, light must pass through the cornea, the aqueous humour, the pupil, the crystalline lens and the vitreous gel.
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