Your eyes were not designed to see well in water, and a diving mask is necessary since it provides an air space between the water and your eyes so that you'll be able to see clearly. For diving, a good mask is absolutely essential. It is the difference between a great diving experience and an average one. A good mask must fit well, not leak, and provide good vision underwater.
Difference Between Diving Masks and Goggles
Why do scuba divers wear masks that cover the nose and eyes, not just goggles that cover only the eyes? The reason is that the nose pocket of a diving mask is needed to compensate for increasing pressure as you dive deeper. The nose pocket allows you to blow air into the mask through your nose, equalizing that pressure. Without this feature, you might damage your eyes and, at the very least, feel a painful sensation at depth. So, remember to breathe out through your nose before you feel any “mask squeeze.”
Parts of a Diving Mask
A diving mask consists of a lens made of tempered glass (absolutely required), a double skirt made from surgical-grade silicone to keep the water out, and an adjustable mask strap.
A diving mask is robust and specifically designed for scuba diving to great depths, which makes it more expensive than the children’s mask that you can buy in a supermarket.