How To Choose A Prescription SCUBA Mask

HOW TO CHOOSE A PRESCRIPTION SCUBA MASK

 
With many Optical Correction Choices Available, this guide is about helping you choose the right one for you.

Near-Sighted, Myopic or Negative Sphere Prescription           
Step Diopter lenses are stock lenses or pre made lenses available in .5 increments.
These lenses adjust only for the near - sighted  (Sphere) available 1.0 to 8.0 strengths.
These lenses are perfect for snorkeling and Scuba Diving!
Step Diopter lenses will not correct for cylinder or astigmatism
Fits only certain masks
 
Custom Lenses for Near & Far - Sighted Rx
A custom lens mask is recommended if you have a cylinder reading greater than +1.0 or less than -1.0.  Using step diopter lenses on the higher astigmatism could cause migraine headaches.  Masks with custom lenses start at $129
Large selection of masks available

 
 
 
How to calculate your prescription or RX for a step diopter lens
 
 OD (Ocular Dexter) refers to your right eye.
 
OS (Ocular Sinister) refers to your left eye.
 
Sphere Refers to the degree of correction needed by your eye, measured in diopters. For nearsighted people this is always (-) negative.
 
Cylinder Refers to the amount of astigmatism in your eye (the degree by which your eye is not uniformly round).
Get your latest Rx from your optometrist
For the best result, you must add one half (1/2) of the cylinder number to the sphere number.
Take care to add or subtract correctly
Follow examples below to select RX

Example 1
                        Sphere   Cylinder   Axis
OD      -3.0                  .0            .0        
OS      -2.0                  .0            .0                 
RESULTS
RIGHT LENS 3.0   LEFT LENS 2.0
OD : Sphere of 3.0, plus of the cylinder 0 : -3.0 + 0 = -3.0
OS :  Sphere of -2.0, plus of the cylinder 0 : -2.0 + 0 = -2.0      
Example 2
                        Sphere   Cylinder   Axis
OD        -3.0         +.50            .0        
OS         -2.0          -.50             .0        
RESULTS
RIGHT LENS 3.0   LEFT LENS 1.5
OD : Sphere of 3.0, plus of the cylinder +.50 : -3.0 + .25 = -3.25
CHOOSE 3.0
WATER NATURAL MAGINIFICATION WILL ALLOW USE ROUND DOWN
OS :  Sphere of -2.0, plus of the cylinder -.50 :   -2.0 - .25  = -1.75
CHOOSE 1.5 
WATER NATURAL MAGINIFICATION WILL ALLOW USE ROUND DOWN
Example 3
                        Sphere   Cylinder   Axis
OD             -3.0         +.1.50         .0        
OS            -2.0          -1.50           .0        
           
RESULTS
CUSTOM
OD AND OS HAVE CYLINDER READING ABOVE +1.0 OR 1.0