Choosing the right diopter for prescription goggles – AquaGear

Use either of these equations to determine the best swimming goggle diopter for your eyes.

(1) Sphere + 1/2 Cylinder = Goggle Diopter

(2) Myopia + 1/2 Astigmatism = Goggle Diopter

Some Examples you can use to determine the correct diopter for Swimming Goggles:

Left Eye: Sphere or Myopia is -5.0. Cylinder or astigmatism is -1.0. Goggle diopter should be -5.0+ 1/2(-1.0) or -5.5

Right Eye:Sphere or Myopia is -5.0. Cylinder or astigmatism is +2.0. Goggle diopter should be -5.0 + 1/2(+2.0)or -4.0

Since corrective goggles are pre-made, they do not cover all diopters in fractions as would regular eyeglasses. If your swimming goggle calculation falls between 2 diopters strengths (-3.75 for example), always pick the lower diopter(-3.5), as this will make focusing easier.

These are rules of thumb; you can contact your eye doctor for specific advice.

A typical spherocylindrical prescription would look like:

OD is an abbreviation for the Latin oculus dexter, meaning right eye. OS is an abbreviation for the Latin oculus sinister, meaning left eye. The first number after the determination of which eye is the sphere. A negative number indicates myopia. A positive number indicates hyperopia. The second number in this prescription is the cylinder (astigmatism), and the third number is the axis of the cylinder component. The axis of the astigmatism does not relate to the amount of cylinder, just the location of the irregularity. If the patient has no cylinder, then the last two columns may remain blank, or “DS” for “diopter sphere” may be used.