Surfing, Swimming and Other Water Sports with Contact Lenses.
It is tough to catch waves when you can't see them coming, but is it safe to wear contact lenses in the water?
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Doctors and the Food and Drug Administration (FDA) strongly advise not going in the water with contact lenses.  There are several reasons for this advice:
1. If you are splashed or you open your eyes under water there is a good chance you will lose your contact lens.
2. Sand and small particles can get trapped between your contact and your eye, scratching the surface of the eye.  This will normally cause irritation and / or vision impairment lasting for a few days and can occasionally be more serious.
3.  The lens can become folded over and damage the eye.
4. Most importantly, it is possible to pick up microbes that can cause eye infection, eye damage, or even blindness.
More About Harmful Microbes and Your Contact Lenses
Harmful Microbes can attach to your contact lenses much more easily than they can to the naked eyeball.  They are sheltered under the contact lens and do not wash out.  The warm, wet environment on the underside of your contact lens is conducive to the rapid development of colonies of microbes.  Once once microbes gain a foothold they quickly multiply and can cause serious infection.  Infection will cause pain, vision loss and possibly blindness.
Swimming Goggles and Contact Lenses
Your eye does not need to come into contact with a lot of water: millions of microbes can live in tiny droplets.  This means that using standard swimming goggles over your contacts doesn’t eliminate the risk of collecting harmful bacteria under your contacts as small amounts of water can still get inside, and once they are in they can breed effectively.
Two Main Factors Influence the Chances of Picking Up Harmful Microbes while Participating in Water Sports:
1. What type of water are you in?  Dirty water is obviously much more likely to cause infection. Lakes and rivers are the worst.  Chlorinated swimming pools and the ocean are better but still pose a risk.  Chlorinated swimming pools add new problems.  Chlorine can damage your contact lens, or worse adhere to it, causing more sever eye irritation. 
2. Water Temperature: In warm water there are higher concentration of microbes and they can also reproduce faster.
Our recommendation:  Do not wear contacts while surfing.   A friend of mine wore contacts on a surf trip to Bali.  She was always careful to wash her contacts well each evening, and leave them to soak properly.  Nonetheless, she picked up an extremely virulent microbe and is now blind in one eye, and partially sighted in the other.  Doctors told her that if she had not been wearing contacts then the microbes would not have been able to establish themselves and she would not have had any problem.
The best, most fail-safe, effective method to protect your eyes from serious microbe damage is to  invest in a pair of prescription watersports sunglasses or prescription swim goggles for swimmers.  Surf Sunglasses are designed for the ocean's roughest conditions. They also have the added benefit of protecting your eyes from strong sunlight, saving you from common surfer eye problems caused by UV radiation.
If you must wear contacts while doing water sports Transworld Surf published a study you will find interesting.   It estimated (based on too small of a sample population) that a contact lens-wearing surfer will lose one lens every 2.7 years, and will experience some discomfort or eye problem every 1.7 years.
There are some preventative measures that you can take to minimize your chances of collecting dangerous microbes in your eyes if you do insist on wearing contacts:
1.  Use disposable contact lenses and through them away immediately after your session.  If you cannot use disposables, rinse then disinfect your lenses as soon as you get out of the water.
2.  Rinse your eyes with sterile saline solution when you get back to your car.
3.  Symptoms like itchy, dry or “sandy” eyes or increased sensitivity to light it may be early signs of a very serious problem.  See your eye doctor immediately.
I understand the desire to wear contact lenses in the water, but do not recommend it. Permanent damage to your eyesight is simply not worth the risk.  Prescription surf sunglasses eliminate the chance of infection, remove the possibility of physical trauma to the eye (which is how I lost my eye surfing), and offer full UV protection so you will see great for years to come.