It looks as if one eye is looking straight (your right) and the left is drifting off (wall eyed or a squint or strabismus). The technical name for this is an exotropia. Did you have any eye muscle surgery as a child? The causes of this include: Previous eye muscle surgery, poor vision left eye which is either old or more recent. What I cannot tell from one single photo is how the two eyes move together. Are you looking straight ahead or are you looking to the left?
You should see an ophthalmologist who will examine your eye movements, do cover tests etc and also examine each eyes vision and health. This can be done by a Strabismologist or a Neuro-Ophthalmologist. SOmetimes they will recommend eye musche surgery or botulinum toxin to one of the small eye muscles which move the eye. JO