Humans and other animals have many phenotypic variations in eye color. The genetics of eye color are complicated, and color is determined by multiple genes. So far, as many as 15 genes have been associated with eye color inheritance. Some of the eye-color genes include OCA2 and HERC2.
Answers (2). green. There are many reasons accounting for the fact that your eyes go out of focus and it is quite normal in the daily life. The tiredness of eyes can result in your difficulty in focusing on object. A migraine headache, as said by the ophthalmologist, can also cause the eye go out of focus.
Answers (2) It make your eyes tired after a long day's hard work. and naturally you get eye strain, It will make you feel burning and dry in your eyes. In my opinion, tiredness does cause eye strain, but eye strain is not the cause of tiredness completely. And your tiredness and eye strain may be caused by your whole afternoon's hard work. 07/26/2013. good (0) Report Abuse. From your description, it is normal that you feel tired and eye strain.