He is likely experiencing a PVD or posterior vitreous
detachment, a common event that happens in many people.
He has a thick gel material in the middle of his eyes. Over time as it liquefies, this gel material collapses on itself and pulls away from the wall of the eye. Sometimes it can stimulate the retina causing him to see flashes of light
. Other times, the liquefied vitreous can clump together to cause the gray floating spot that he sees.
It is recommended that he see an ophthalmologist
to look at the retina to make sure there are no problems such as a retinal hole or tear. In most cases, there are no problems, but this exam in precautionary and allows for preventative treatment of any lesions that are found.
If he notices a sudden increase in floaters, flashes of light (like a lightening storm), or a shadow/veil in the periphery of his vision, this can be worrisome for a retinal detachment
. He would need to contact his ophthalmologist promptly in that case.Please remember to press the accept button so I can receive credit for assisting you.