The very front surface of the eye (the cornea) can most simply be thought of as spherical in shape. This special shape provides most of the light-focusing power to the eye.
Usually the front surface is not actually spherical but more oval in shape. This difference in shape is usually small. When the cornea becomes less and less spherical, the more light focuses irregularly on the retina. The common type of astigmatism, called regular astigmatism, is easily correctible with glasses or contact lenses.
- Visual Efficiency Exam
- Dilated Health Exam
- Specialty Contact Lenses
- Corneal Reshaping (Ortho-Keratology)
- Sports Vision
- About Astigmatism – COVD
- NEI Guide to Refractive Errors
- How Stuff Works – Astigmatism