Contact lenses are worn on the cornea of the eye to enable a person to see well (with 20/20 sight) or for cosmetic purposes (to change eye color). Contact lenses come in many different varieties to address the vision correction needed. Millions of users wear contact lenses now.

Only small minorities of wearers encounter problems, which consist of:
  • Scratched cornea
  • Infection
  • Adherent lens
  • Lost lens

Only 4 in 10,000 wearers develop infections. The vast majority of users have no problems, once they are taught proper application and care of their lens.