Prescription Diving Mask | Prescription Swimming Goggles | Prescription Scuba Mask
Free Shipping Over $20 Australia

How to Choose Corrective Lens & How to Choose Prescription Swim Goggles

How to determine your lens power for your goggles and diving mask

For use in the water (an already-blurry environment), step diopter (or dioptre) is used to determine lens power for your swimming goggles and diving masks.

The first step to choosing prescription goggles is determining the diopter strength that most closely matches your current prescription.

Formula is:

Sphere + 1/2 of the cylinder = Diopter strength

 Sphere is the degree of weakness in diopters. This is always a negative number for nearsighted people, and a positive number for farsighted.

Cylinder is the degree of astigmatism in your eye. Add half of this number to the sphere to determine diopter strength.

 

For example:

 

Sphere

Cylinder

O.D. (right eye)

-4.50

-1.25

O.S. (left eye)

-5.00

-1.00

 

Calculated Diopter strength is as below:

 

Calculated Diopter Strength

Diopter Strength (rounded)

O.D. (right eye)

-5.125

-5.00

O.S. (left eye)

-5.50

-5.50

 

 

Astigmatism

If you have low astigmatism, say cylinder is less than 2.00, our corrective lenses will fit you well. It provides economic and quick way for you to see clearly in the water.

However, if you have high astigmatism, our corrective lens goggles may still a solution, but may not produce the best result as you wear prescription glasses. You may need a custom-made product for best visual results. Please contact us at admin@swimfun.com.au to see what we could help.

 

Note:

  1. A general rule when choosing a diopter lens is to round down — rather than up. In practice, due to water reflection, some people like to wear swimming goggles that is less around 0.5 sphere. This places less strain on your eyes.
  2. This measurement is only a suggestion. You may like to choose right diopter per your own experiences

 

Choose the Goggle Model

There are both recreational and racing styles of prescription goggles.

Serious swimmers and lap swimmers will want to buy a racing style and should look for low profile frames, or those with "racing" in the model name.

Swimmers who rarely do lap swimming and just want an alternative to going without glasses in the water — such as masks or goggles with larger lenses — should look at recreational models. These have more generously padded frames and offer wider peripheral vision.


There are no products to list in this category.