Contact lenses have become a popular form of vision correction due to their ease of use and relative safety. While they've been on the market for nearly 50 years, contacts still pose some risk to those who do not take proper precautions.

Types of contacts

Users have several choices of lenses: one-day disposables, two-week disposables, extended wear lenses and rigid gas-permeable lenses.

Fitting

Contacts are fitted to the wearer's eyes by an optometrist or ophthalmologist. Obtaining lenses that do not fit the wearer's eyes, either through online retailers or by sharing them with a friend, can result in eye irritation, slippage of the contacts on the eye and poor vision.

Extended wear

Wearing contacts longer than their intended use can cause a lack of oxygen to the eye. Contacts indicated for use for two weeks, for example, should only be worn for two weeks. Extended wearing can cause infection of the eye and compromise vision. Additionally, contacts that are not rated for overnight wear should not be slept in as sleeping can reduce the amount of oxygen available to the eye.

Storage

With the exception of daily disposables, contacts are to be placed in a clean container filled with contact lens solution at the end of the day. Prior to placing them in the solution, wearers are usually instructed by their doctors to rub the contact gently with contact lens solution before storing them. Failing to clean the contacts increases the risk of conjunctivitis and other eye infections.

Allergies

Some wearers are allergic to certain brands of contact solutions, causing redness of the eye and irritation.

Source:

All About Vision: Q&A on Contact Lenses