Contact lens FAQs

Published July 2, 2016

• Reviewed by Christine W. Sindt OD, FAAO

on Sept. 1, 2016

What is my risk of infection?

Research following outbreaks of rare but serious eye infections in the United States shows that serious infections occur most often in contact lens wearers who do not take proper care of their contact lenses and cases.

Nearly one-third of contact lens wearers experience a contact lens-related red or painful eye that requires a doctor’s visit.

How can I reduce my risk of infection?

You can significantly reduce your risk of infection by following good lens care and hygiene practices. Wear your contact lenses the number of hours recommended by your doctor and replace as prescribed.

Remember that a contact lens is a foreign-body placed in your eye, and you need to take care to make sure it stays uncontaminated.

Could I have an eye infection?

Wearing contact lenses puts you at a higher risk for infections and ulcers.

A good rule of thumb is the RSVP rule for contact lenses:

Redness in one eye or both
Secretions can be tearing, clear stringy mucous, yellow or green sticky mucous
Vision changes typically mild to moderate decrease in vision or blurring
Pain — may be aching, sharp, dull, or just uncomfortable

If you have any of these symptoms, remove your contact lenses immediately. For this reason, it is important to always have an up-to-date pair of back-up glasses.

Do not attempt to treat a red eye yourself; go to your eye doctor as soon as possible. Non-preserved artificial tears may be used, however avoid Visine and other "get the red out" drops, and never use someone else’s eye medications.

What are good contact lens care and hygiene practices?

Hygiene is vitally important to preventing infection. Some of these methods vary with the type of lens you are using. Follow the instructions of your eye care provider.

Always wash and rinse your hands thoroughly before handling your lenses. Studies have shown that simple measures such as hand-washing prior to touching contact lenses will significantly reduce the likelihood of getting an infection.
Keep all water away from contact lenses. Avoid showering while wearing contact lenses and remove them before using a hot tub or swimming.
Don’t soak or rinse your lenses in tap water or saline.
Use fresh lens-disinfecting solution.
Don’t place a lens in your mouth for cleaning or wetting.
Discard used solution from the contact lens case and clean it with fresh solution — never water — every day.
Store your contact lens case upside down with the caps off after each use.
Clean your lenses on a regular basis as indicated by your eye care practitioner.
Discard all solutions one month after opening, even if there is still solution remaining.
Clean your lens storage case in warm soapy water at least once a week and leave to air-dry with the lid off every day.
Replace your lens case at least every three months and we recommend replacing it every month (new lens cases are often sold as a package with bottles of solution).

When do I use rewetting drops?

A dry eye becomes uncomfortable. The lens may feel gummy or sticky and your vision will become blurry or hazy. Ideally, with contact lens wear you should blink approximately every 6 to 8 seconds. This, however, is difficult to do when you are concentrating on your computer, a book, or a video game.

You may use rewetting drops as often as you need to. The trick to using your rewetting drops is to use them before your eyes become too dry. Once your lens is dry, it attracts deposits and gets dirty. Then most drops won’t help. You will need to remove the lens and rub it with your solution to clean and re-insert it.

If your lens moves onto the white of your eye:

Don’t panic.
It’s okay to keep the lens in your eye.
It may be uncomfortable, but it will not damage your eye.
The lens cannot go behind the eye.Use rewetting drops frequently.
Always use your lids to push the lens back onto your cornea so that you don’t scratch your cornea.

Can I sleep in my lenses?

Sleeping in contact lenses continues to be a major risk factor for corneal infection, even for high oxygen permeable materials.

Patients considering the convenience of extended wear lenses should realize that they increase their chances of getting a corneal infection by 4 to 7 times if they sleep in their contact lenses.

If you have extended wear lenses, lower your risk by maintaining good hygiene, and follow your eye care practitioner’s advice as to lens wear and replacement schedules. In particular, don’t sleep in your lenses if there is any discomfort.

Can I swim in my lenses?

We do not recommend it, however, wear good fitting goggles if you go swimming with your contact lenses.

If you have gone swimming without goggles, make sure you remove and thoroughly clean and disinfect your lenses at the first opportunity before re-inserting them.

Do not sleep in lenses if you have been swimming.

Why can't I use my glasses prescription to get contact lenses?

Contact lenses are classified by the FDA as a medical device and therefore are regulated differently than glasses. Because you are actually putting a contact lens on the surface of the eye, there are risks for infections, ulcers, and other complications that are not present with glasses.

Other measurements made for contact lenses include:

The curvature of the cornea (the clear tissue at the front of the eye that the contact lens sits on)
The diameter of the contact lens with respect to the diameter of the cornea
Position of the eyelids
The health of the surface of the eye and the surrounding lids is also taken into account

The lens corrective power often differs from the glasses prescription. This is because glasses sit about 12 mm from the eye, and contact lenses sit right on the eye. In order to account for this distance between the glasses and the eye, a mathematical calculation is made to determine the appropriate contact lens power.