If your child gets any kind of a chemical in his eye, like a household cleaning product or a pesticide for instance then treat it as an emergency.
Quickly take him to the sink and pour warm (never hot) water into his eye for a full fifteen minutes. If there is another adult present they can hold the eye open while you pour the water in using a clean glass. This may be difficult but it’s extremely important to cleanse the chemicals from his eye to prevent permanent vision loss.
Then bring your child and the container of the chemical to the hospital (A&E) as soon as possible.
You should always keep any chemicals or anything harmful to your children well out of their reach.