Get your eyes checked!

[UptonSinclair]

I prefer plastic frames, so there isn't much adjusting. When I had metal frames with nose pieces, I just bent the nose piece by hand. One thing you have to do is get a good measurement of your current glasses to make sure you buy the correct size. Arm length and total width are the most important. There is some wiggle room as long as you don't buy something too different. I have a big head, so I have to make sure to get a larger size.