Scuba diving is a fun activity and it is a pity to miss out on all the beauty underwater because you can’t see properly! A very large percentage of divers require correcting their vision to see clearly. What options do they have to correct their vision while diving? There are two options available: One is to use prescription masks; the other is using your contact lenses.
Can you scuba dive wearing glasses?
Prescription Diving Masks are ideal for those who wear glasses and are not confident or comfortable wearing contact lenses. Some divers wear their glasses under the mask. This might work if the arms on the glasses are very thin and flexible. Most likely the mask will leak. Other divers take the arms off an old pair of glasses and mount the front part of the glasses in the mask. The mask will not leak and the visual correction will be OK; but it will be hard to clear the mask and almost impossible to avoid fogging!
Fortunately, there are several options for buying or making a prescription dive mask. The easiest is to buy a dive mask that has been designed so that you can put a separate, off-the-shelf corrective lens in for each eye. These lenses typically come in 0.5 diopter jumps. You should round the prescription down to the nearest available lens as it is better to be slightly under corrected than over corrected. This is only an approximate visual correction but it is fast, easy, and relatively inexpensive. In many cases the off the shelf lenses will do a good job of correcting your vision. In addition, the dive mask already magnifies everything by 25%.
What type of contact lens should you use?
There are two main types of contact lenses: hard and soft. Both can be used for diving. When we dive, the gas in your mask is under the same pressure as the gas in your lungs. Therefore, the tears and surface of the cornea take up inert gas (nitrogen in air) just like the body absorbs it from the gas in the lungs.
Hard Lenses
Hard lenses won’t allow gas to penetrate. This might cause some blurry vision after the dive. Why does this happen? The eye – like all body tissues – absorbs nitrogen, and when you ascend this nitrogen slowly escapes the eye. The hard lenses won’t allow the nitrogen to escape therefore tiny bubbles will form between the lenses and eye causing blurry vision. You could experience slightly dryer eyes and have to blink more than normal. Hard contacts are usually smaller and therefore the risk of them falling out is more likely, when the dive mask is flooded. Because of the before mentioned reasons hard contact lenses can be used but are not really recommended for scuba diving.
Soft Lenses
Soft lenses allow gas to penetrate letting air pass through the lenses. Eyes will not feel dry when diving. When ascending, you will not have the same bubbly experience as using hard lenses. Soft lenses are slightly larger. If you flood the mask you will be able to hold the lens inside by just closing your eyes, slightly. The eyelid will hold the lens inside. Disposable, soft contact lenses work perfectly underwater and they are a very cost effective option for divers with bad vision. Many people question whether the contact lens will come out if the mask floods, there will always be a chance of this happening but there are many divers who dive with contacts regularly and have never experienced this problem. If you feel like it could be a problem, just close your eyes whilst you clear your mask. The main thing to ensure you do is clean your contacts and wash your eyes once you have dived; this ensures that any salt or muck is removed.
In conclusion, contacts can be worn while diving. Soft contacts are preferable to gas permeable contacts and gas permeable contacts are preferable to hard contacts. However, all contacts can be safely worn while diving if a few simple precautions are taken. If you lose or flood your mask, keep your eyes closed to reduce the risk losing a contact. If you are wearing soft contacts, you might be able to simply squint for 30 seconds to stick the contact to the eye and then carry on. Soft contact lens wearers need to be careful using defogging solutions and take special care to clean and disinfect their contacts after diving. If you are wearing hard or gas permeable contacts, remember to ascend slowly for the last 10 m and all divers wearing contacts should consciously blink more often while diving.
So there you have it… Bad eyesight is not a problem when diving; you just need to get yourself a prescription diving mask or some disposable contact lenses.
