My now 3 and a half year old got glasses at 18mo. I had a strap across the back so it wasn't easy to remove herself. I put them on and did something really distracting - going for a walk, going to the park etc.

I know many people are of the opinion that you should break in gently but for me, and my DD, I thought it was better to make it a rule that the glasses were on always.

Good luck!