If you are new to shopping for Contact Lenses online, here are some important definitions of terms:

     Cornea - outer most membrane of the eye.  The protective layer that your contact lens comes in "contact" with.

     Iris - the color portion of your eye.

     Pupil - the opening through which light enters to be reflected onto the retina. The black dot in the center of your eye.

     Retina - the back most portion of the eye containing blood vessels and nerve endings.  Responsible for assimilating the image to the brain.

Vision Problems

The eye is an extremely intricate, complicated and delicate part of the body. Just like any complex camera or optical system, the smallest deviations from the norm can throw the entire function off. As vision is so very important, it is imperative that people pay close attention to their vision needs. Taking care of your eyes is just as important as taking care of your health.

There are four primary types of vision problems:

Myopia (nearsightedness)
Myopia is most often caused by an abnormally long eyeball. The implications of myopia are that an individual is able to see objects near to them clearly, but unable to focus in properly on distant objects. Because the eyeball is extra long, distant objects are focused short of the retina, blurring the projected image. This problem can also be caused by a very steep curvature of the cornea, causing extra refraction and the same effect as the elongated eyeball. Myopia is the most common vision problem, affecting Over a quarter of the population. It is caused by heredity and will usually surface by the time a child is 12.

Hyperopia (farsightedness)
Hyperopia is the opposite of myopia and occurs when the eyeball is abnormally short. The result is that light rays are not yet in focus when they arrive at the retina, resulting in a blurred image. It too can be caused by an abnormal curvature of the retina. Although almost all children demonstrate a slight degree of hyperopia while young, it is most often compensated for by other parts of the eye and it's effects decrease as they progress through their teens.

Presbyopia (aging eye)
Presbyopia results when the crystalline lens in our eyes loses its suppleness and becomes less flexible. This happens naturally with age and negatively affects the ability to focus close-up. It often becomes noticeable after the age of 40 and results in a need for bifocal or multi-focal lenses to see clearly at all distances.

Astigmatism (uneven cornea)
Astigmatism is the result of uneven curvatures of the cornea and results in an inability of the eye to focus clearly at any distance. Instead of the cornea being round like a baseball, it is has a more oval shape, similar to a football. It is often associated with myopia and causes light to focus at more than one point on the retina. The result is that objects at all distances appear distorted. It is very common to have a small degree of astigmatism, which is literally indiscernible. Very often, astigmatism is inherited.

Vision problems that are left uncorrected get worse. It is important to visit an eye care practitioner yearly, as vision overall worsens as we age. As well, any vision problems that may not be noticeable to an individual can be diagnosed by an eye care practitioner, and appropriate steps taken or plans made to address the problem or potential problem.

OS: Left Eye
OD: Right Eye
OU: Both Eyes

Brand: Manufacturer & Series of lens

Power/Sphere: Strength of lenses - a number between –20.00 and +20.00

BC: Base Curve (back curvature of lens) -a number between 8.0 and 10.0

DIA: Diameter (diameter of lens) - a number between 13.0 and 15.0
Toric and custom lenses have additional measurements that may include AXIS and Cylinder.

Cylinder: Correction for Astigmatic patients (toric lenses only)
(a number between -4.00 and +4.00)

Axis: Correction for Astigmatic patients (toric lenses only) - a number between 0 and 180

A replacement contact lens

A replacement contact lens is a contact lens that you are already wearing successfully and has been prescribed to you by a licensed eye care professional. A replacement center supplier can only provide you with replacement lenses and suggests that you consult with your eye care professional on a regular basis.

Contact lenses come in different sizes and must be fit to your eye by an optometrist or ophthalmologist. A replacement center supplier can not sell you contact lenses that you are not already successfully wearing. You will need to consult your eye doctor and get a new prescription before changing your brand.

A replacement center supplier can not and will not provide advice about your prescription, corrective requirements, or which lenses are best for you.