Is it normal to have one eye with nearsightedness and the other is normal vision?

I'm not sure if it s considered nearsightedness. Cuz I don't know the difference between nearsightedness and farsightedness. My left eye cannot see objects that are far away but it can see stuff up close. My right eye is normal vision. So pretty much I can see clearly cuz my right eye helps a lot. I'm 14 and had this problem checked out probably last year? I noticed this happened 2-3 years ago when I closed my right eye during school. My friend told me that I could strain my right eye if I didn't get glasses or something? But when I got it checked out by the eye doctor the guy said it was fine and I could probably put one contact lense in my left eye (if it bothered me). I chose not do anything so right now i have one eye with horrible vision and the other eye is normal. Please help me! I have no idea what to do! Should I go back to the eye doctor?!