Teach your child to wear sunglasses!
Sunlight contains harmful UV radiation. Too much exposure to sunlight as a child is harmful to the eyes. Children under 10 have the greatest risk for retinal damage from the sun, since their eyes do not have the same ability as adults to protect from UV radiation. This damage does not become apparent until after they become adults.
All sunglasses are not alike. Ordinary sunglasses can make things worse. Dark lenses cause pupils to dilate, letting in more of the UVA rays that damage the lens and retina. Look for sunglasses that block both UVA and UVB radiation. Check to make sure the sunglasses fit well and are not damaged. It is best for the lenses to fit close to the eye. The lenses should be impact resistant and should not pop out of the frames. Choose lenses that are large enough to shield the eyes from most angles. Also, find a wide brimmed hat for your child to wear along with the sunglasses.