People generally wear scuba diving masks and swim goggles when swimming, diving, snorkel or other explore underwater. Light travel condition in air is different from that underwater. Objects watched underwater are larger and closer than they actually are. In addition, light rays can not travel effectively from eyes to target object through water. Masks and swim goggles provide a chamber of air in front of the eyes that enables the eyes to see things clearly and correctly. This is the reason why people need masks or swim goggles underwater.
If you have eyes problems including myopia, hyperopia or astigmatism, you also need to wear diving masks or swim goggles with corrective lenses, in order to see get clear underwater vision. However, the prescription may need to be changed because the distance from eyes to the lenses of goggles is different from that between eyes to eyeglass lenses. There are two types of lenses in prescription diving masks, one is lenses with prescription in entire area and the other is prescription lenses inserted between the mask face shield and eyes. Customers should consult some opticians to choose suitable masks or goggles.
Generally, diving masks are designed to be large and rectangular for scuba diving or snorkeling. Most masks are made of silicone so as to resist deterioration and allergy. If the diving mask comes with prescription lenses, manufacturers can make it according to customer’s specific measurements and corrective needs. Of course, there are pre-made masks with prescription lenses which have equal correction in both of the lenses. If you are not astigmatic seriously, pre-made lenses are right.
Another kind of masks has a fixed lens area that allows the insertion of prescription lenses. This kind of masks is convenient, because wearers can select different lenses according to different conditions. You don’t need to insert lenses when you are wearing contact lenses. However, not all contact lenses are suitable for diving. There are several kinds of emergency that may happen when swimming and diving. For example, Gas permeable lenses may fall into eyes below certain depths because of water pressure.
Though swimming goggles look like diving masks, they are much smaller and smoother than diving masks. Also, swim goggles with pre-made prescriptions which are designed for farsightedness and nearsightedness are available and provide clear vision. Lenses of diving masks and swimming goggles can be made in several materials, such as glass, acrylic, plastic and so on.
Customers can require eyewear providers to help in adapting eyeglass prescription for use in goggles or masks. However, the prescription must be from an eye doctor.