If you wanna take your little kids under 6 years old for some outdoor activities under the strong sunshine, letting them wear shades may be cool and a useful protection in many parents' minds. From optical doctors' perspective, it can make sense for children below 6 years old for 1-2 hours wearing sunglasses, which can protect their eyes to some extent. However, it may have some bad effects on these young generations' eyes for a long time wearing. Due to some vision functions of children which are mostly not mature enough, their eyes require much more sunshine to stimulate, so that shades for protection may affect the development of their eyes when they are young. What's worse, it might lead to weak sight problems to some degree. To conclude, before 6 years old, you'd better not let your children to wear shades or sunglasses, even they look lovely or cool with them.