The outside corners of my eyes slant slightly upwards. Can surgery make them slant downwards?

Ideally, the outer corner of the eyes (lateral canthus) should be higher (about 2mm) than the inner corners for best aesthetic outcome, especially in females.  It is rare for them to be too high.  If so, lateral canthoplasty can be done to reposition the outer (lateral) canthus.  See an oculoplastic surgeon for evaluation.

Your eyes should slant a little upwards on the outside corner. If you look in the mirror or at a picture the outside corner should be a little higher than the inside. If it is lower it will make you look sad.    

Thanks for your question. Without an examination or photographs it is almost impossible to give you an accurate answer. If it is just a minor problem I'll probably suggest that you just leave it alone.   The corner of your eye can be very delicate And when you get a blunting of this area.