Foreign Bodies in the Eye
Most material that gets in children's eyes is organic (dirt, sand, leaves, etc.) and can easily be flushed out with saline or tap water. Eye irrigation should be thorough. A child will often struggle with this since it is uncomfortable, but be persistent. Hold the child's head steady and run the irrigation solution (water or saline) back and forth over the surface of the eye to remove as much material as possible. If you believe there is still material in the eye(s), take your child to the doctor.
If the material in the eyes is chemical, flush the eyes immediately and copiously (longer than you think you need to), and take the child directly to the ED to be examined.