Why are my eyes different to each other? (Photo)

Unfortunately, there can be a few causes of why you have the unevenness in the upper eyelids.  It may be that one eye is more recessed in the skull or one eye comes out farther from the face.  This can rarely be caused by a medical disorder such as hyperthyroidism.  Most likely, this is due the the fact that we all have asymmetries in our face and everything is completely normal.  To be on the safe side, if this is new change and you have signs of hyperthyroidism, I would get by an ophthalmologist.   As long as everything checks normal from a medical standpoint, you can look into options to improving this asymmetry.  I hope this helps.   

From the image is appears that the only difference is the amount of skin above your eye. The shape of your eye and where your upper and lower lids cross the globe are all the same. More skin in your upper lid can be caused by brow droop bring in brow skin to the upper lids or just more upper eye lid skin. If your brows are symmetrical, then it is just simple upper eyelid skin excess. Good luck.

It seems like you could have eyelid retraction which is related to graves disease. Read more about graves disease at my website denvereyelid.com. You need to see an oculoplastic surgeon.