A contact lens is a corrective, cosmetic or therapeutic lens usually placed over cornea of the eye.
Contact lenses serve the similar corrective purpose as conventional glasses but are lightweight and virtually invisible. It has benefits for wearers like better appearance and practicality. Also they do not steam up, provide a wider field of vision, and are more suitable for a number of sporting activities.
Contact lenses can now correct almost all eyesight problems including:
- Myopia (short-sightedness)
- Hyperopia (long-sightedness),
- Astigmatism
- Presbyopia (age-related reading problem).
Types of contact lenses
Different types of contact lenses that are available are –
- Disposable contact lenses– These are designed to be worn from one day to one month, depending on the lens material. They often have high water content and are usually made with thinner, more flexible materials. One-day contacts are disposed of after each use but longer term disposable contacts must be cleaned and disinfected after each removal. Disposable contacts can be prescribed for daily use or extended wear, depending on the brand and purpose in question.
- Daily wear contact lenses– Daily wear contacts are intended to be worn for an entire day, generally around eighteen hours, and are designed to be comfortable for hours on end. Daily wear contacts can be reusable or disposable
- Extended wear contacts-Daily wear contacts must be removed before sleeping but extended wear contacts can be comfortably worn both night and day. Extended wear contacts might be convenient but there may be some health risks involved like risk of ulcerative keratitis(ulceration of cornea)
- Spherical contact lenses– These are used to treat myopia, hyperopia and presbyopia.
- Multifocal/Bifocal lenses– These are used for patients of presbyopia. These lenses can provide two or more corrections that gradually shift throughout the contact to provide corrective refraction for aging eyes, both alone and in conjunction with additional disorders.
- Toric lenses– Toric lenses are cylindrical lenses that rely on gravity and lid interaction to rotate to the right angle in order to see clearly.
Precautions
If you choose to opt for contact lenses follow these precautions-
- Always wash your hands with a mild soap and dry them with a lint-free towel before touching your lenses.
- Always use fresh, unexpired lens care solutions
- Always clean your lens case daily and let air dry.
- Always remove contacts before you go swimming.
- Never allow soaps, cosmetics, or other substances to come into contact with your lenses.
- Never wear your contact lenses in the presence of harmful or irritating vapors or fumes.
- Never wear your lenses beyond the period recommended by your eye care professional.
- Never swap contact lenses with anyone.
- Never touch the tip of a lens care solution bottle to any surface, including your finger or the contact lens.
Complications
Wearing contact lenses is not without risk. You must be aware of the potential hazards and accept these relative risks in addition to the benefits of contact lens wear. Complications like corneal abrasion(scratch over cornea), allergic reactions, new vessels formation(neovascularization) over cornea, corneal ulcer and conjunctivitis. Following the above precautions will be helpful in reducing the risk of these complications.
Even with the many recent advances in spectacle lens technology and the rising popularity of surgical interventions such as laser eye corrections, the use of contact lens remains a safe, effective and inexpensive way of achieving clear comfortable vision for many people.
Discuss with your ophthalmologist if you wish to choose contact lenses for you.
By,
Dr Prerna Gaur
Acknowledgements
https://www.sciencedaily.com/terms/contact_lens.htm
#Thinkhealth blog 