Contact lenses are a medical device that allow a patient/customer to correct their refractive error by placing a super thin piece of light transmissible material directly on the eye. While there are a number of different types of contact lenses available, it is always important to consult with a local optometrist to determine the best fit and parameters of a contact lens that works best with your eyes.
A great reference is also at the American Optometric Association's website: LINK