Wearing a properly fitted scuba mask is essential to enjoying clear vision while exploring the amazing world under the surface of the ocean. The scuba mask provides an air pocket so human eyes can focus underwater.
Make certain that the scuba mask you are wearing is authentic gear designed for scuba diving and not just some version of swim goggles. Be sure your nose is enclosed within the air pocket to adjust for air pressure changes as you dive, and that the mask is constructed using tempered glass rather than plastic, which can fog up and distort, or regular glass, which can shatter. If you normally wear prescription eyeglasses or contact lenses, you can get a scuba mask made using your specific eyeglass prescription.
When you first try on the mask, be sure that the seal is comfortable and securely fits all the way around. Try wearing the mask without putting on the strap by inhaling through your nose. A mask that fits properly will stay there via suction without falling off. The best masks have a wide strap for easier adjusting throughout your dive as necessary.
Before your first dive wearing the scuba mask, scrub it using toothpaste or a soft scrub cleanser to remove any chemical coating on the glass that may cause the mask to fog up. This cleansing procedure is only necessary the first time you use a new scuba mask. After that, simply use a defogging solution prior to each dive to ensure clarity.
As you try the scuba mask on for the first time, check to see that it provides maximum viewing angles - not only up and down, but from both sides as well. Try to choose the smallest mask that still feels comfortable on your face, as larger masks tend to add drag as you are diving.
You may also be interested in special features like a purge valve that can be used to blow water out of the mask, although this is more a convenience than a necessity. You can purge water from your mask simply by pulling the mask slightly away from your face until it fills with water. Then while pushing the upper part of the mask against your forehead, exhale to drive the water out from the bottom of the mask.
You should visibly check the condition of your scuba mask prior to each dive to note any damage to the rubber seal or lens. Whenever you are descending in water, keep exhaling through your nose to equalize the water pressure in the mask and prevent it from being pushed into your face from the build-up of external water pressure.
Invest in the best quality mask you can afford, because someday your life could depend on it.