There are two types of lenses prescribed for correcting or improving vision. These include:

Eye Glasses

Eye glasses, the most common form of eyewear used to correct or improve many types of vision problems, are a frame that holds two pieces of glass or plastic, which have been ground into lenses to correct refractive errors. Refractive errors can include nearsightedness or myopia (difficulty seeing far away), farsightedness or hyperopia (difficulty seeing close up), and astigmatism (blurring due to an irregularly shaped cornea). Eye glasses perform this function by adding or subtracting focusing power to the eye's cornea and lens.

Contact Lenses

Contact lenses are worn directly on the cornea of the eye. Like eye glasses, contact lenses help to correct refractive errors and perform this function by adding or subtracting focusing power to the eye's cornea and lens.