as you have undergone retinal detachment
surgery you should not do gym work out after the surgery.double vision
is because during surgery , some ocular muscle is hooked to tie scleral band.
do not worry about double vision, it will be normal after some time.
vision after retinal surgery
depend upon condition of macula, whether retina is attached or not. get your retina checked regularly for its attachment and macula
do not do weight lifting, breathing exercises