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Glossary of Common Contact Lenses-Related Terms

Aspheric - a thin contact lens with gradually changing power

Astigmatism - condition in which the cornea has an irregular curvature, often but not always occurring with hyperopia or myopia

Axis - precise location of the point where correction is needed on the eye

Base Curve - a number between 7.0 and 10.0 or a phrase, such as steep or flat, that describes the curvature of the eye

Bifocal - contact lenses with two or more viewing zones

Cleaning Solution - a liquid solution that aids in removal of debris from contact lenses

Colored lens - a contact lens with a tint or color added, either for handling/visibility purposes or to enhance or change eye color

Colorblends - brand name of colored lenses, Freshlook Colorblends

Cornea - referred to as the "window of the eye," it is the outermost layer of the eye

Corrective lens - see contact lens

Contact Lens - thin plastic material designed to fit over the cornea for the correction of a refractive error.

Cylinder - measurement of how much correction is needed for patients with astigmatism

Daily wear Contact Lens - contact lenses that are worn for one day

Deposits - accumulations of substances (usually protein) onto the contact lens

Diameter - the width of the eye, measured in millimeters

Diopter - measurement unit of the refractive correction of a contact lens

Enzyme cleaner tablets or Solution - see Solution

Eye Care Provider (ECP) - see Optometrist, Opthalmologist, or Optician

Flat medium - a base curve of 8.6 or 8.7

Farsightedness - see Hyperopia

Glaucoma - a condition in which the pressure inside the eye is elevated to a point that can damage the optic nerve and cause a loss of peripheral vision, or blindness

Hyperopia - a condition in which a person can see clearly at a distance but not up close

Light filtering tint - designed for sports use, these tints help objects stand out against a background

Monovision - technique to limit the effects of presbyopia by correcting one eye for hyperopia and the other for myopia.

Multifocal - a contact lens with more than two viewing zones

Myopia - also known as nearsightedness, a condition in which a person can see clearly up close but not at a distance

Nearsightedness - see Myopia

OD - Oculus Dexter, Latin for right eye

OS - Oculus Sinister, Latin for left eye

Opthalmologist (MD) - medical doctor who specializes in eyes. Can perform exams, treat disease and perform surgery

Optician - not a medical doctor, but licensed to fit and dispense eyeglasses and contact lenses following written prescription from ophthalmologist or optometrist

Optometrist (OD) - performs exams, diagnoses and treats disease. In some areas they prescribe, fit and dispense eyeglasses and Contact Lenses

Oxygen permeability - the amount of oxygen diffusing through contact lens material under specified testing conditions

Power - see Sphere

Presbyopia - also known as farsightedness, a condition in which a person can see clearly at a distance but not up close

Rewetting Solution - used as a lubricant to increase comfort

RGP (Rigid Gas Permeable) lens - a contact lens made of slightly flexible plastics that allow oxygen to pass through to the eyes

Rinsing Solution - liquid solution that removes debris from contact lenses in preparation for use

Rx - prescription

Solution - there are many different types of solutions, made for different types of contact lenses

Sphere - a measurement of how much correction is needed, it is a number between -20 and +20.

Steep medium - a base curve of 8.3 or 8.4

Tint - depending on the contact lens, there are different types of tint such as a handling or visibility tint, light filtering tint, enhancement tint or color tint

Toric - contact lens designed to correct astigmatism by bearing two different powers at right angles

Visibility Tint - lightly tinted lenses for easier insertion and removal

Visitint® - brand name, lightly tinted lenses for easier insertion and removal