My father is 59 years old. 10 days back he had lasor operation for kidney stone. He is taking antibiotics and painkillers. From last 3-4 days he is complaining of floaters during day. He says when he see with concentration he see floaters and during night some kind of white flash in right eye. He says ' ek lashkara sa padta hai'. He is wearing specks from many years. From some months he is using eye drops x-fresh carboxymethyl cellulose eye drops just for eye cleansing. He never faced any eye problem before in his life. No decrease in vision and no pain . Please tell me why is it happening? Is this something serious?