It may be that you are too fatigue and your eyes get too tired without adequate rest or sleep so that you see light spots in front of you when you close your eyes. If the condition is serious, which means that you cannot sleep well because of the light spots or the light spots cause headache and so on, you should go to the doctor's for an overall examination and correspondent treatment. Besides, you should pay attention to have adequate rest and sleep, and do not over your eyes. Regularly do some eye exercises such as massaging around your eyes for a few minutes to relieve the fatigue and nervous muscles.