Hello, Gray shadow in the vision is commonly caused by the clumping together of the collagen fibers in the vitreous humor due to ageing. You may perceive it as floaters or shadows. Other medical conditions that may have similar symptoms are cataract, glaucoma, optic neuritis, etc. You are suggested to get clinically examined by an ophthalmologist, get required tests and investigations done. You will be given conservative treatment or your treating doctor will recommend surgery will depend on the pathology detected. Get treated at the earliest. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician