Goggles or Mask?

Why is it that we never see anybody diving with these little goggles that only cover the eyes in scuba diving?

Well the reason has to do with pressure and atmospheres, you see as you descend down much like when you drive up a mountain or fly in an airplane you might experience a ringing in the ears. This is a sign that you've gone up or down an atmosphere but how do we overcome it? We pinch the nose and blow to pop the ears back to normal, well just like this everyday practice the same is occurring below the surface.

Along with the ringing in the ears, as you descend further down there is more pressure pushing on your body. The idea of increases in atmosphere and pressure comes from Boyle's Law. An example that they use in textbooks would be a balloon, as you increase in atmospheres so too does the pressure increase so by pulling the balloon further down the air inside of it is being compressed. Much like the human lungs which are represented by the balloons they too are being compressed by the surrounding wall of water. Both the balloon and the lungs have a cavity filled with air. Guess what else has this cavity of air? The mask, so you can assume the same is occurring within the mask.

The reason why we don’t see people scuba diving with a pair of goggles is because there is no additional air coming into the cavity, in scuba diving if you experience the “squeeze” then you should exhale air through the nose but if you have just a traditional pair of goggles then this is not possible. If you look close, after a diver surfaces he/she may have a ring/band around their face from where the mask was positioned. This is a sign of the mask possible being too tight or that the diver didn't exhale some into his/her mask to combat the pressure.