You have mild left upper eyelid ptosis.
This can be addressed with ptosis surgery. A careful consultation needs to be performed to determine if you have latent ptosis on the right side. Commonly both sides have a degree of ptosis but the one that is worse is more obvious. After surgery to fix the heavier eyelid, the other side drops. This is called Herring's law ptosis. This is prevented by a careful preoperative assessment which sometimes produces a recommendation for bilateral ptosis surgery rather than just on the obvious side.
Very difficult to answer with the limited view on the photo. It is unlikely that this is an orbital problem - an examination would determine whether or not this is an issue. The more likely difference is in the brow position - it is very common for one brow to be higher than the other unless the frontalis muscle is completely relaxed. If you have not other symptoms, this is not something that has to be fixed. If it is weighing heavily on your mind, than an examination by an Oculoplastic surgeon would be an option for you.