A quick explanation and background of a progressive addition lens is necessary in order to understand the importance of choosing the proper lens for your needs.

A progressive lens gives people an array of prescriptions - placed in the proper positions throughout the lens - to best imitate normal vision. Imagine having the precise correction needed to see a television screen more than 15 feet from you, while reading this article on your desktop computer, and then looking down at your...

Keratoconus is an eye disease in which the cornea deforms from its normally curved dome shaped and becomes cone shaped. Sometimes there is a flaw in the collagen, the material of the cornea that weakens and allows the cornea to stretch into an irregular cone shape.

The cornea is the clear tissue located at the front of the eye and it refracts and focuses light as it enters the eye. Therefore abnormalities of the corneal surfaces can severely distort vision.

Symptoms usually start in...