If far-away reef, fish, or your buddy look blurry, choose a nearsighted diving mask with prescription (minus lenses) matched to your glasses.

Simple strength rule (myopia):

Use your glasses SPH for each eye, then round down by 0.50–0.75 (toward zero).

Pick 0.75 down for longer sessions to reduce eye strain; 0.50 down is fine for short swims.
Example: Glasses −3.25 → choose −2.5 for all-day snorkeling.

Snorkel or scuba?
Every mask here is suitable as a prescription snorkel mask and also as a prescription scuba mask (low volume, tempered glass). Select your diopter, then pick the frame that fits Small/Medium or Medium/Large faces.

Good to know:

Minus lenses typically available in 0.50 steps (e.g., −1.00 to −9.00).

Astigmatism (CYL) isn’t directly corrected in off-the-shelf lenses, use SPH only; you’ll still see a big improvement. Many customers say its like weraing there glasses.

Check your recommended strength with our calculator, then choose your fit.