My left eye is quite nearsighted but my right eye is fine? Why?

Good luck. No good reason. But when you hit your 40's, you'll be grateful you can read with that eye without glasses. If this nearsightedness was not present when you were younger, then it's cataract.

Related Questions

Hi doc, I want to ask whether lasik eye is dangerous or not? I have floaters and nearsighted. Left eye around 700 and right eye around 600. Thanks!

Usually safe. Lasik has a very low complication rate. You need to get a preop exam and testing of corneal thickness, curvature, tear film and production, corneal health, and other factors to make sure it is ok for you. I have successfully treated thousands of patients with your prescription. It will not get rid of your floaters. It should reduce or eliminate your dependence on glasses. Good luck! Read more...
Lasik. Lasik is not dangerous in appropriate candidates. It is one of the safest most common elective procedures performed in the U.S. Read more...