What is the difference between nearsighted and farsighted lenses?

Nearsighted lenses have a negative SPH value and correct distance vision. Farsighted lenses have a positive SPH value and correct close-up vision.

How do I find the sphere (SPH) value on my prescription?

The SPH value is usually in the first column of your prescription. A negative number indicates nearsightedness, while a positive number indicates farsightedness.

How Should I Adjust My Prescription for Clear Vision Underwater?

Select a lens strength 0.50 to 0.75 diopters weaker than your regular prescription to compensate for underwater magnification.

Can I choose a lens strength that isn’t listed in the dropdown?

If your exact strength isn’t available, pick a lens 0.50 to 0.75 diopters weaker than your prescription to maintain clear vision underwater.

Can I choose different lens strengths for each eye?

Yes, you can select different strengths for each eye if they are available in the dropdown.

How do I upload my prescription during checkout?

You don't need to upload it. Contact us via chat or email if you require specific strengths or assistance.

What happens if I accidentally choose the wrong lens strength?

Contact customer support immediately. We may be able to correct the order depending on its processing stage.

Are your lenses safe for both snorkeling and scuba diving?

Yes, all lenses are certified HD Tempered glass and safe for snorkeling and scuba diving up to 100ft.

How long does it take to receive lenses, and can I track my order?

Orders usually take 7-14 days to process. A tracking number will be provided via email upon shipment.

What is your return or exchange policy for prescription lenses?

You have 30 days from delivery to return your mask. For full details, visit our returns policy on the Oceans Optics website.

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Safety Survival Whistle with Nylon Bolt Snap

Name: Safety Survival Whistle with Nylon Bolt Snap
Brand: Oceans Optics
SKU: 4000153033048-1 Piece
Price: 7.0 GBP
Availability: InStock

Safety Survival Whistle with Nylon Bolt Snap

Freebie Friday: Add to cart to claim yours!

Quantity

£7.00 GBP

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Free Delivery

Product Description

Designed for those who crave both clarity and adventure, the RX Carbon Dive Mask offers precision vision and ultimate comfort for every dive. With RX-ready lenses, it’s easy to customize for crystal-clear underwater vision, whether you’re nearsighted or farsighted.

This mask is ideal for adventurers looking to document their underwater experience. The built-in action camera mount allows you to attach your GoPro or other action cameras, so you can effortlessly capture every breathtaking moment. Perfect for travel vloggers, underwater photographers, or anyone wanting to relive their dives with precision.

The elastic headband provides a comfortable, tangle-free fit, keeping your hair out of the way, while the silicone skirt ensures a secure, leak-proof seal no matter your face shape. Plus, the quick-release strap lets you easily adjust your fit, making it perfect for on-the-go dives.

Mask Sizing Chart

Rx Action - Size Guide

Rx Action

Size Category: Large
This mask comfortably fits most medium to larger face shapes.

	Min (cm)	Max (cm)	Optimal (cm)
Width	10.5	12.5	11.25
Height	7.9	10	8.75

Available Variations

Lens: Nearsighted or Farsighted
Face Seal / Frame Color: Black only
Action Camera Mount: Included

Free Shipping

Please allow 5-18 Days for us to get the product ready and get it to you. We want it to be perfect.

30 Day Return Policy

No returns on Whistles. Sorry it's just gross.

Free E-guide with every purchase

Snorkelling 101: Your Ultimate Guide to Better Aquatic Adventures

Now free with every order! Access your eGuide instantly after checkout or via email, and dive in at your own leisure.

View full details

Let customers speak for us

from 858 reviews

Fantastic!

The last time I went snorkeling (more than 10 years ago) I wore contacts. At age 65, glasses only. I thought I was done snorkeling, until I found these! They worked perfectly! I could see the fish. And at around 80 bucks for the mask and a breather tube, it's a bargain. They charge like $25 to rent them at the beaches when you go on a cruise (and it is gross using something that was in someone else's mouth!) I highly recommend these if you are near-sighted and want to snorkel.

GoBucksJoe

Rx Obsidian Prescription Snorkel/Dive Mask_Medium

03/03/2025

Ecellent mask, i can finally see! Wow, im so happy i found this site!

Jewell Schinner

Rx Action Prescription Snorkel Mask w/Cam Mount_Large

02/26/2025

Great fit, great view.

Received my prescription mask. It fits great and I am looking forward to actually being able to see the world underwater for the first time.

Marian Brown

Rx Obsidian Prescription Snorkel/Dive Mask_Medium

02/25/2025

Great mask

Had no idea that I could order a prescription mask for my husband! Ended up being the best gift ever for our trip to Cozumel. Amazing mask and spot on!

Suezq

Rx Carbon: Nearsighted Mask for Scuba Diving - Large

02/18/2025

I could see!!!

I have been unable to wear contacts for the past 5+ years , so ordered this mask with the 7 (highest) lens. Took a snorkel trip in Belize. The guide pointed out sting rays buried in the white sandy bottom - sea urchins tucked in reefs - I saw all of it - better than contacts with a regular mask. Best pre vacation purchase ever!

Meg S

Rx Obsidian Prescription Snorkel/Dive Mask_Medium

02/18/2025

I can snorkel!!!

It has been more than a decade since I went snorkeling. At age 65 I no longer wear contacts lenses. Finding prescription goggles (at a very reasonable price) was a blessing! Without correction, everything would be a blur. But I was able to see the fish and the rest quite clearly!

Plus it was comfortable. If you need prescription lenses for distance, these are worth it.

Additionally, they came pretty quickly.

GoBucksJoe

Rx Obsidian Prescription Snorkel/Dive Mask_Medium

02/17/2025

Great mask and can see without glasses!!!

Great quality mask!!!

Steve Goode

Rx Carbon: Nearsighted Mask for Scuba Diving - Large

02/16/2025

Great fit, and an amazing buy!!

Even though I haven’t tried the in the water yet I am super happy with my purchase!!