It is most probably due to paresis
of some of your extra-ocular muscles. You need to consult a neurologist
or an eye specialist (squint specialist) .
You might be having squint of very less deformity
which is not noticeable easily by you. Drooping of lid is due to ptosis which once again needs to be examined by a neurologist or eye specialist in clinic.
Meanwhile, when you have to do fine work, you can bandage the affected eye or sometimes by keeping the head in a particular posture, this diplopia
can be overcome.