What is the primary purpose of a prescription for contact lenses?

The primary purpose of a prescription for contact lenses is to ensure proper sight correction and fit. This aspect is crucial because contact lenses are medical devices that need to be tailored to an individual's specific vision needs and eye shape. A valid prescription not only specifies the correct refractive power needed to correct vision issues, such as nearsightedness or farsightedness, but also includes parameters that ensure the lenses fit the cornea properly.

Proper fitting is essential for comfort and to avoid complications such as corneal abrasions or infections that can arise from poorly fitting lenses. Therefore, the prescription serves both to correct vision accurately and to promote eye health by securing an appropriate fit for the lenses being used.

While cosmetic enhancements can be a consideration with certain colored or cosmetic lenses, they do not represent the primary reason for a prescription. Similarly, serving as a recommendation for specific brands or limiting the number of lenses sold does not directly relate to the essential purpose of ensuring effective visual correction and comfort through proper fitting.