Bruises and black eyes are not uncommon for children. Bruises are not usually serious but occasionally can be cause for concern. The blue/black colouring of a black eye is caused by blood pooling under the skin and is generally caused after a trauma to the eye area. You will need to make sure that the eye itself hasn’t been injured.
You will need to check with your G.P. to make sure that your child’s black eye is simply a bruise especially if you didn’t see the injury occur.
If your child is having vision problems, doesn’t appear to be able to move his eye normally, or is in severe pain, then he will need immediate medical attention. Take him to the hospital (A&E) immediately.
Occasionally, if your child suffers from allergies then this can result in a black eye. Your G.P. will be able to check this.