Do glasses work underwater?
Yes, it’s possible to make glasses that allow you to focus underwater. You could use a high-index material with a concave lens, or a low-index material (such as air) with a convex lens.
Why do dive masks cover the nose?
Why do scuba divers wear masks that cover the nose and not just goggles? Goggles seem lighter and handier. 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 the diver to blow air into the mask, equalizing the pressure.
Can you go blind from chlorine water?
Chlorine gas reacts with the water on your eye to form hydrochloric acid, which can cause blindness. The chlorine in pools is a safer combination of hypochlorous acid and hypochlorite ions. But this can react with urine, sweat and by-products in the water to form chloramines that cause irritation.
Why can I see perfectly underwater?
By wearing a flat diving mask, humans can see clearly underwater. The scuba mask’s flat window separates the eyes from the surrounding water by a layer of air. Light rays entering from water into the flat parallel window change their direction minimally within the window material itself.
Will a nearsighted person who wears corrective lenses in her glasses be able to see clearly underwater when wearing those glasses?
This difference in how the light refracts between water and glass, compared to air and glass, means that glasses would not correct your vision underwater, because the glasses would not put the light on a correct path into the eyes to create a clear image.
How do you not breathe through your nose when scuba diving?
Along with your eyes, your nose is enclosed inside the diving mask. The mask makes a seal onto your face, so it is impossible to breathe in through it. There’s a flexible pocket around your nose so that you can still pinch it to equalize your ears as you descend on the dive.