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Author Question: Describe the different levels of DFDs. (Read 28 times) |
Astigmatism is the most common vision problem. It may accompany nearsightedness or farsightedness. It is usually caused by an irregularly shaped cornea, but sometimes it is the result of an irregularly shaped lens. Either type can be corrected by eyeglasses, contact lenses, or refractive surgery.
The ratio of hydrogen atoms to oxygen in water (H2O) is 2:1.
Human stomach acid is strong enough to dissolve small pieces of metal such as razor blades or staples.
Increased intake of vitamin D has been shown to reduce fractures up to 25% in older people.
The eye muscles are the most active muscles in the whole body. The external muscles that move the eyes are the strongest muscles in the human body for the job they have to do. They are 100 times more powerful than they need to be.