Glossary

Lacrimal Gland - Almond-shaped gland that secretes tears into the eye. It is located in the upper outer region of the orbit.

LASEK - Laser in situ Epithelial Keratomileusis - A technique of laser refractive eye surgery that is used to correct myopia, hyperopia and astigmatism. An alcohol solution is used to soften the epithelium (first layer of the cornea) and this is moved to the side whilst an excimer laser is used to reshape the central part of the cornea (stroma) producing surgical flattening of the cornea. The epithelial layer is then replaced and a bandage contact lens is worn for a few days to aid healing.

LASIK - Laser in situ Keratomileusis - Laser refractive eye surgery used to correct myopia, hyperopia and astigmatism. A thin corneal flap is created either using a blade or by laser pulses (Femtosecond), then an excimer laser is used to reshape the central part of the cornea (stroma), producing surgical flattening of the cornea and then the flap is replaced.

Lensmeter - An instrument used to measure the refractive power of an artificial lens, such as a spectacle lens.

Low Vision - Generally refers to a severe visual impairment, not necessarily limited to distance vision. This applies to all individuals with sight who are unable to read at a normal viewing distance. The visual impairment may result from a degenerative disease, trauma or a congenital condition that cannot be corrected by refractive, medical or surgical means.

Lucentis - Ranibizumab - By its chemical name is an anti-angiogenic drug that has been approved to treat wet age-related macular degeneration (AMD). It is administered by injection into the eye. Anti-angiogenics is a class of drug that prevents the formation of abnormal new blood vessels and dries up vessels which are have already begun to leak.

Lutein - A naturally occurring organic pigment (carotenoid) found in green leafy vegetables, which has also been found as a yellow pigment in the macula region of the central retina. It helps to protect the macula from oxidative stress and absorbs harmful blue light. It can also be taken in the form of a supplement that in some studies has been shown to decrease the risk of AMD by increasing the amount of the macula pigment.