Prescription Swim Goggles
The Choice is Clear
Because glasses and contact lenses are impractical in the water, many goggle brands have begun producing prescription strength goggle lenses to help nearsighted swimmers see clearer underwater. Prescription swim goggles are identical to regular recreational or competitive goggles in design. Oftentimes, swim brands will simply take a popular traditional-lens goggle and make it available in a wide variety of diopter strengths. Both recreational and competitive goggle models are available in prescription strength options. However, most brands only manufacturer negative strength lenses for near-sighted folks (also known as myopia). As a result, positive strength lenses are far rarer to come by. Ranging from -1.5 all the way to -10.0, these helpful goggles can help any swimmer see more clearly in and out of the water. These ready-made lenses are designed to closely match your contact or glasses prescription strength. Using an optically correct goggle can help you keep a close eye on the competition and allow you to easily see and track your split times while swimming.
Static vs. Replaceable Lenses
Many prescription swim goggles are available with static diopter lenses. This means that the lenses are not replaceable. These types of goggles are popular because it means less worry and fuss for a swimmer. All a swimmer has to do is slip a pair on and is ready to swim with perfect 20/20. The only drawback of fixed prescription lenses is that they are not able to adjust to a swimmer's eyesight as it improves or diminishes. Sometimes, you can purchase two static lens pairs, disassemble and swap out the left and right eyes and end up with two pairs of prescription lens goggles.
There are also prescription strength goggles that are available with interchangeable lenses. Swimmers can purchase a standard goggle frame and replace the regular lenses with specifically designed corrective lenses. While these types of adjustable goggles do require a little more work, many swimmers prefer them. Interchangeable lenses means that swimmers can get a fully customized goggle that's able to adapt to their changes in eyesight. Because two prescription levels can be mixed and matched, these types of goggles are also ideal for swimmers who have eyes with two different diopter strengths.
Choosing Prescription Swim Goggles
Although similar to your glasses prescription, swim goggle diopter lenses require a quick calculation to ensure that the proper strength is selected and post-swim headaches are avoided. Looking at your prescription, you'll want to locate the sphere and cylinder for each eye. Use the following formula to find the right diopter lens for you:
Find Your Diopter Strength
(1/2)(Cylinder) + Sphere = Diopter
Example: If your left eye (OS) has a sphere of -4.5 and a cylinder of +.25, your diopter strength would be as follows:
(1/2)(.25) + (-4.5) = -4.375
Remember: Water will refract light and correct vision a bit without any prescriptive power applied. With that in mind, if your calculation does not end with a .5, select a diopter strength that is one step lower than the outcome of your calculation. If you need help, please give us a call or open a chat session for guidance.
If your astigmatism is over 2.0, you will likely not feel comfortable in a typical prescription goggle and may want to opt for a custom-made design. However, if your astigmatism is under 2.0, you should be fine going with a pre-made goggle.