Accommodation
The ability of the natural crystalline lens to adjust and - with the natural contractions
of the muscle in the eye - focus on objects through a range of near, intermediate
and far distances.
Accommodating intra-ocular lens
As with the natural lens, an accommodating lens moves and flexes, in response to
ciliary muscle contractions in the eye. These contractions drive forward movements
of the lens so the eye can maintain a clear image as it focuses on near, intermediate
and far objects.
Crystalens® is the first and only
accommodating lens approved by the FDA.
Age-Related Macular Degeneration (pronounced mak-you-lar dee-jen-er-ei-shun)
(AMD)
An eye condition in which the centre of the retina (the macula) is slowly damaged,
affecting central vision.
Amsler Grid
A chart of grid lines and a central dot used to find and check problems with central
vision.
Antioxidants
The nutrients that neutralise and deactivate free radicals.
Aspheric
In relation to spectacles and contact lenses refers to the shape/design of the lenses;
not quite spherical. Aspheric spectacle lenses are popular among people who
have strong prescriptions because they are thin and lightweight, and reduce distortion
and eye magnification.
Aspheric contact lenses can enhance optical design that creates crisp, sharp vision
beyond what you are likely used to -designed to reduce halos and glare - especially
at night and in low light.
Astigmatism
A condition in which the cornea is irregularly shaped, which prevents light rays
from focusing so that near and distant objects appear blurred or distorted. Glasses
and toric contact lenses (gas permeable and soft lenses) can correct astigmatism.
Cataracts
A clouding of the lens inside the eye so that light cannot get through to the retina.
Conjunctivitis
Inflammation of the conjunctiva, characterized by a pink eye. The cause is either
infectious or allergic, though the term "pink eye" is commonly used for any type
of conjunctivitis. Other symptoms include burning, discharge, dryness, itching,
light sensitivity, eye pain or discomfort, stickiness and tearing.
Cornea
The outer, transparent, dome-like structure that covers the eye's iris, pupil, and
anterior chamber. Part of the eye's focusing system that transmits and focuses light
into the eye.
Crystalline lens
The transparent, double convex (outward curve on both sides) structure behind the
iris. The lens of the eye helps to focus light rays onto the retina.
Daily Wear Contact Lenses
Contact lenses that are worn during waking hours but removed at the end of each
day for cleaning and disinfecting.
Diopter
Unit of measure for the refractive (light-bending) power of a lens; eye care practitioners
use it in eyeglass and contact lens prescriptions. A negative number refers to nearsightedness;
a positive number, farsightedness. For example, someone with -8.00 diopter lenses
is very nearsighted, while someone with +0.75 diopter lenses is only slightly farsighted.
Disposable Contact Lenses
Disposable lenses refer to the replacement frequency of the contact lenses.
This can range from daily disposable, designed for single use and then discard or
disposable lenses which are worn on a daily basis and then cleaned daily between
use and then discarded upon Eye Care Professional's advice, often 2 weekly or monthly
Dk/t
Dk/t is a measurement used to quantify the amount of oxygen that is transmitted
through the contact lens. The higher the Dk/t value; the higher the amount
of oxygen transmitted through the lens.
Extended Wear Contact Lenses
Contact lenses that have been approved for overnight wear. Extended wear contact
lenses are typically approved for up to 7 days/nights of overnight wear or up to
30 days/nights of overnight wear between removals for cleaning and disinfection
or disposal.