rx

Reading your RX for your Prescription Snorkel Mask

Finding the right lenses for your mask

Examples of Optical Prescriptions

Sample 1

 

RX

SPH

CYL

AXIS

DISTANCE VISION

D.V.

O.S. (RIGHT)

-3.50

.25

 

O.D. (LEFT)

-.25

-1.00

 

 

 

 

 

 

NEAR VISION

N.V

O.S. (RIGHT)

 

 

 

O.D. (LEFT)

 

 

 

 

 

 

 

 

This Rx is a (DV) Distance reading only.  Looking at the Right (OS) the spherical reading of -3.50 and the cylinder reading of -.25 we would calculate with -3.5 plus one-half of the cylinder -.25 equals to -3.63 or rounding down it would be -3.5 diopter.

Now, Looking at the left (OS) spherical reading -.025 and the cylinder reading of -1.00 we would calculate with -0.25 plus one-half -1.00 to equal to -.75 and rounding down to a plano  (zero strength) lens because half step diopter lenses start at -1.0.

Lenses needed for Sample 1  -     Right Lens -3.5 and Left Clear or Plano Lens

Sample 2

 

RX

SPH

CYL

AXIS

DISTANCE VISION

D.V.

O.S. (RIGHT)

-4.50

.25

 

O.D. (LEFT)

-2.0

-1.00

 

 

 

 

 

 

NEAR VISION

N.V

O.S. (RIGHT)

+2.0

 

 

O.D. (LEFT)

+2.0

 

 

 

 

 

 

 

This Rx is  (DV) Distance reading and (NV)  Near Sighted.

Looking at the Right (OS) the spherical reading of -4.50 and the cylinder reading of -.25 we would calculate with -4.5 plus one-half of the cylinder -.25 equals to -4.63 or rounding down it would be -4.5 diopter.

Now, Looking at the left (OS) spherical reading -2.00 and the cylinder reading of -1.00 we would calculate with -2.00 plus one-half -1.00 to equal to -2.50 and use -2.5 diopter

The Near Vision reading is a +2.0 in both eyes thus the bifocal or reading lense would be the plus 2.0

Lenses needed for Sample 2   -Right Lens -4.5 and Left -2.5 Lens for a snorkeling mask

Custom ground lenses to accommodate both near and far would be needed for a scuba mask to see gauges.