Prescription Glasses & the Marine World

Once upon a time it was a massive undertaking to get ‘adjusted’ masks for diving and snorkelling. Nowadays, for certain scripts, it is much easier!

The type, model and size of mask will be directly affected by your personal eye script, as everyone’s eyes are different.

If you have your script available, please send it through so we can advise you correctly.  We have over 18 years’ experience with fitting the generic script lenses for scripts, so I hope we can assist you soon.

When light passes through different substances (eg, in a mask it goes through water, then glass and then air to your eye), it ‘bends’ making the item appear different to its actual size & position in the water.  We compensate for this when recommending a dive/snorkelling mask.

There are three main types of script/adjustment we can assist you with. For more information on what definitions we refer to, please see the generic script below.

Sample Prescription



For SHORTSIGHTED persons – your ‘Sphere’ would be a NEGATIVE number. Unlucky you, as the bending of light actually worsens your script by about half a dioptre. So if your script is a -3.5, I would recommend a -4.0 for use in water.

FULL LENS – For Short-sighted divers

For LONGSIGHTED persons – your ‘Sphere’ would be a positive number. Lucky you, as the bending of light actually improves your script by about half a dioptre. So if your script is a +3.5, I would recommend a+3.0 for use in water.

FULL LENS – For Long-sighted divers


This refers to bifocal/reading requirement. We have lenses with clear glass for the main, with a bifocal section at the bottom only. Again, this is a POSITIVE dioptre, so a slight step down is the recommendation with this.

BOTTOM THIRD LENS – For divers needing assistance to read gauges/computer/camera details

If you have ‘multifocals’ or ‘graduated lenses’ with a SPHERE and an ADD measurement – this is very personal and specific to your eye and we would be unlikely to fix this completely with general lenses. Depending on your script we would refer you to a custom-made lens company who custom make your mask lenses to suit (similar to your own special eyeglasses – fit to you)


This refers to astigmatism or shape of your cornea, and this I cannot assist with – if your astigmatism is quite strong, or you have a combination  of both ADD and SPHERE I may refer you to a custom lens specialist to have lenses specifically made for you. This takes a little longer, but I can recommend OzBob’s work – he, as an optometrist, has been making diving masks for many, many years. It is a more expensive event, however these are made to order for your specific script items, so the price is applicable.For more details – look up my colleague:

OzBob Prescription Masks


The masks below are capable of all three different types of lens.

Tusa Freedom Ceos Mask: – $140.00 (Pricing as of June 2017)

TUSA Freedom Ceos Mask

Lenses $68.00 per lens (All same pricing)

·        Shortsighted Lenses made for this mask ~ -1.5 to -8.0 in 0.5 increments

·        Longsighted Lenses made for this mask ~ -+1.0 to +4.5 in 0.5 increments

·        Bifocal Lenses made for this mask – +1.0 to +4.5 in 0.5 increments

Scubapro Zoom Mask $144.00 (Pricing as of June 2017:)

Scubapro ZoomEVO Mask

Lenses – prices differ:

·        Shortsighted Lenses made for this mask  ~  -1.0 to -4.5 in 0.5 increments – $68.00 each

·        Longsighted Lenses made for this mask ~ +2.0 to +4.0 in 0.5 increments – $79.70 each

·        Bifocal Lenses made for this mask ~+1.0 to +3.0 in 1.0 increments – $79.70 each


I would strongly recommend a black silicone skirt to help your eyes focus underwater, and avoid glare (like sunglasses!) which will tire your eyes.

It’s good to pick a memorable colour so you can tell at a glance that it is your special corrective lens mask, and to also have a Neoprene Mask tamer fitted to the strap:

·        Visually – to identify your personal mask

·        You can write your name on the neoprene strap

·        Slows the masks sinking speed if you drop it in the water

·        Makes it much easier to adjust strap, and more comfortable to wear

·        Great for taming long hair

TUSA Neoprene Mask Tamer

I hope these details make it easier to make decisions on a prescriptive mask – they are worthwhile, and need only a little extra care than a standard mask, but help you see the underwater world in a clearer, more enjoyable manner!

Email me at – I hope to hear from you soon to assist you further with seeing clearer under the surface!