When they're in the water, swimmers who wear eyeglasses or contact lenses could benefit from prescription swim goggles.
These special types of sports eyewear require a prescription that is different from a regular eyeglasses prescription because of the unique characteristics of an underwater environment. Water itself acts as a magnifier, which is why fish in a tank or other underwater objects sometimes appear larger than they actually are. Since light travels and bends differently through water than it does through air, your eye care professional will need to modify your eyeglasses prescription so your underwater sports eyewear gives you the same clear vision your glasses provide on dry land.
Also, depending on the style of swim goggles you choose, an adjustment to your prescription may be necessary because the corrective lenses may be positioned closer or farther from your eyes than the normal position of your eyeglass lenses.
Swimming goggles are much smaller and fit closer to your eyes than a diving mask. They are designed to protect your eyes from the water and be sleek and unobtrusive at the same time, so as not to interfere with your speed and motion. A rubber or silicone seal surrounds the lenses to keep water away from your eyes.
Swim goggles are available with pre-made prescription lenses that are the same power for both eyes. Because swim goggles generally are used in a pool setting, these pre-made prescription lenses will usually provide adequate vision. However, custom-made prescription swimming goggles are also an option.