You asked

What should I do if my child gets something in his eye?

If your child seems to have something in his eye, keep him from rubbing it, this will prevent the cornea from being scratched. If the object isn’t dislodged by blinking, wash your hands and see if you can locate what’s irritating the eye. You can do this by pulling the lower lid slightly downward and the upper lid slightly upward.
If the object looks embedded in the eye, don’t try to remove it as this could cause further damage. Seek immediate medical attention.
If you can see the object floating around in the eye, gently and carefully remove it with a cotton swab. If this doesn’t work then use lukewarm water try to flush it out. The easiest way to do this is to hold your toddler over a sink and gently pour warm water from a clean glass into the corner of his eye. 

More questions

Children's eyes are sensitive so it is vital to protect them from the sun's harmful rays.
Your young child can have their eyes tested even if they can't read
Regular eye exams are essential in order to monitor your child's eyesight.
There are some signs to watch out for if you think your child may have a vision problem. 
Should your child get any kind of chemical in her eye you should treat it as an emergency and bring her to the hospital immediately.
You should take your child to their G.P. or to the hospital if you notice any of these symptoms. 
You should seek immediate medical attention if an object seems to be imbedded in your child's eye. 
If your child appears to have something in his eye you should seek immediate medical attention if it is imbedded in the eye. 
As your baby learns to crawl and begins to explore her surroundings you will need to child proof your house to prevent eye injuries.
Babies and young children are always getting up to all sorts of mischief and eye injuries are quite common. It is important to always consult with your G.P. should any eye injuries occur.