I am a biologist and study the effects of UV radiation. Knowing how important UV protection is, I was very careful to have my new baby protected from the sun's harmful rays- including her eyes.
I purchased Baby Banz sunglasses online just as summer was beginning. These sunglasses come in small sizes especially for little ones, and have a soft neoprene band that keeps them from being pulled off. The band is adjustable with a velcro closure and is easy to work with.
Initially my daughter didn't like the feeling of the sunglasses on her face, but I don't think it was because they were uncomfortable. After a few minutes of keeping her from messing with them, she left them alone. When I took them off her there were no marks on her head or face that suggested to me they were too tight.
These little sunglasses are really adorable, and come in tons of colors for all ages of babies. I would highly recommend them for parents of little ones who plan on spending a lot of time outdoors in the summertime.