Why do different ethnicities have different rates of myopia?

Myopia refers to the situation where light rays are focused in front of the retina and spans a spectrum from mild to severe. It can also have several different causes, but most commonly is due to an elongated eyeball. Some kinds of cataract can also cause increasing myopia by themselves. Myopia, by itself, does not necessarily affect the safety of cataract surgery. For experienced cataract surgeons, performing cataract surgery safely (without complications) even in very high myopes is not particularly difficult.

In general, soft contact lenses are a lot more comfortable than rigid gas permeable (RGP) contact lenses. They are also much easier to fit, and can give very good vision. Both soft and RGP lenses may be suitable for many people. But each has their potential pros and cons. For example, soft contact lenses maybe a little more drying to the eye than RGPs, and for people with very high spectacle powers, sometimes soft contact lenses may not allow such a long period of wear each day because of issues with oxygen transmission with thick lenses.