One of my eyes look more open than the other. What causes this? (photos)

I agree, your brows are in excellent position.  The lifting muscle in the eyelid may have stretched out causing eyelid ptosis.  Please consult with an Oculoplastic Surgeon to evaluate and treat this common issue.  Good luck.

The problem is not the eyebrows. The problem is the left upper eyelid is droopy, called eyelid ptosis. The treatment would be left upper eyelid ptosis surgery. See an oculoplastic specialist for evaluation.

You have a slight ptosis of the left upper lid.  Since this lid is lower, your brow is higher since it is trying to pull up the lid.  When  you correct the ptosis the brow should fall and they will be more even.  See an oculoplastic surgeon who can evaluate the lid muscles and decide what surgery would be best for you.  

Thank you for your question and shared photo. You have a droopy (ptotic) left upper eyelid. This can be easily corrected with one of a few techniques by an experienced Oculoplastic Surgeon. Recovery is 1-2 weeks and results are usually excellent. Good luck.

The upper eyelid on your smaller eye is ptotic, likely congenitally.  A correction would involve shortening the levator aponeurosis of that upper eyelid so the resting position is even with the other side.  It can be performed with a standard blepharoplasty.  

Thank you for your question. It looks like you have left upper lid ptosis (droopy eyelid). It can be surgically corrected. You should consult with an oculoplastic surgeon in your area. Good luck.

Hello,Yes, the reason is you have left eyelid ptosis.  Having said that, we all have asymmetry in our facial bones, orbital volume and orbital fat volume.  So some inherent asymmetries naturally occur with all of us, but you have eyelid ptosis.  Take comfort in knowing this is easy to correct!Good luck.

You have a condition known as blepharoptosis, which is a drooping of the eyelid.  Your photographs display ptosis or drooping of the left upper eyelid.  Due to the drooping, your brain is compensating by elevating the left eyebrow in an attempt to lift the drooping left upper eyelid. The treatment is surgical correction of the drooping left upper eyelid.  The procedure is usually performed under local anesthesia with sedation as an outpatient.  Once the eyelid is corrected, the eyebrow heights will usually return to normal and symmetric positions.

Thanks for the posted photos of facial slight asymmetry. Causes are related either to anatomic, genetic, familial issues or nerve/muscular issue. Appears as left over compensation of the lid due to ptosis of the left upper lid by contraction of left forehead muscles thus causing elevated left eyebrow, But the ptosis of the left lid is still present. 

It seems the upper eyelid is less full on your left side compared to the right. The left eyelid is also droopy. These are signs of ptosis. Ptosis can be due to the aging process, trauma, chronic inflammation, contact lens wear, amongst other things. Systemic etiologies for it should also be ruled out, eapecially if a patient is experiencing other symptoms like double vision, weight loss, etc. it is best to seek the help of an oculoplastic surgeon who sees your kind of case on a regular basis to discuss your surgical options and work up. Best of luck!