Why is my left eye getting smaller while my right eye seems to grow? (photo)

The photograph suggests you have right upper eyelid retraction. The most common cause for this is related to an autoimmune that can affect the thyroid gland.  Your PCP or an ophthalmologist can assess you for Grave's disease. 

The problem could be due to eyelid position change and/or eyeball position change. Best to see an oculoplastic specialist for evaluation. Skype consult is available.

Your eyeballs themselves are not changing in size. Rather the position of the eyeball in the eye socket is changing and/or your lids are drooping or retracting. I suggest you see a medical doctor specializing in eye diseases and surgery-an ophthalmologist-or better yet, an ophthalmologist with subspecialty training in plastic surgery of the eyes-oculoplastic surgery. There are several good oculoplastic surgeons in the Sacramento area.

Thank you for your question.  Based on the photos provided, I would see a specialist for a comprehensive evaluation.  Eyelid retraction can be caused by a thyroid related condition and should be worked up.  Other causes include overcompensation of ptosis or droopiness of the other eyelid, resulting in lifting of the brows and lids to compensate.  An in person examination should determine the cause.  Best wishes.   

Hello bb20161986,
You have retraction of the right upper lid and slight retraction of your right lower lid. I cannot tell from the picture if your eyeball is in correct position. Whats the cause? It could be a few different things but one of the most common cause is thyroid disease. Your appearance is correctable and you can have good aesthetic results. First I suggest getting to an oculoplastic surgeon or an ophthalmologist to discuss this.
Cheers.