Material: Contact lenses can be made from various materials, including soft hydrogels (commonly used for daily wear), rigid gas permeable (RGP) materials, and hybrid materials that combine features of both soft and RGP lenses. The choice of material depends on factors such as comfort, breathability, and prescription requirements.

Vision Correction: Contact lenses are primarily used to correct vision problems, including myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and presbyopia. They can also be used to change the eye color for cosmetic purposes.

Design: There are different designs of contact lenses, including spherical lenses for myopia and hyperopia, toric lenses for astigmatism, and multifocal lenses for presbyopia. The design ensures that light entering the eye is properly focused on the retina.

Usage: Contact lenses can be categorized as daily wear, extended wear, disposable, or rigid gas permeable. Daily wear lenses are removed each night, while extended wear lenses can be worn continuously for an extended period. Disposable lenses are replaced on a regular schedule, while rigid gas permeable lenses have a longer lifespan and require proper cleaning and maintenance.

Size and Shape: Contact lenses come in various sizes and shapes to fit the curvature of the eye. They are available in different base curve and diameter measurements to ensure a comfortable fit.

Prescription: To obtain contact lenses, an eye care professional must conduct a comprehensive eye examination and provide a prescription that specifies the lens parameters, such as power (diopters), base curve, and diameter.