Wednesday, October 07, 2009

Learn How To Read A Contact Lens Prescription

Power of the lens describes the value up to which the lens can correct the error in the sight.
The prescription also includes the some definitions which are:
OS Left Eye
OD Right Eye
OU Both Eyes

The prescription for patients with Astigmatism correction or refraction error correction includes two more columns named:
Cyl or Cylinder

Difference between eyeglasses prescription and contact lenses prescription
1. The eyeglasses prescription includes only the power while the contact lenses’ prescription includes some other terms as well which describes the size of the lens.
2. The power of contact lenses is different from the eyeglasses power because the lenses are place right above the eye cornea while your glasses are usually place almost 12mm away from your eye.
3. The prescriptions for contact lenses also contain an expiration date.