Contact lenses come in direct contact with a very sensitive and important part of your body—your eyeball. Contacts if worn improperly (and sometimes even when worn correctly), can cause changes to the eye, specifically the cornea. We evaluate the cornea for changes such as neovascularization (new blood vessels), swelling, microcysts (air bubbles), and changes in corneal shape. If any of these are present, then a different type of contact needs to be prescribed. Also, vision changes can take place,(sometimes you will not even be aware of these changes), and your prescription will need to be changed.