My 9 Yr Old Son Has Had Involuntary Eye Movements

My 9 yr old son has had involuntary eye movements for about 3 weeks now. We thought it was a sinus infection because he was having pain on his eye lids along with the eye movements. He finished his melds and the pain is gone but not the eye movements. It's not a constant thing but very noticeable. Every time his eyes move together up and to the right side. He does not know they are doing it.