Left eye is getting small. Now to cure!

According to your history, it seems that you have Ptosis. Ptosis is a condition that occurs when one or both upper eyelids droop and the edge of the upper eyelid falls towards or over the pupil, making the eye look smaller than the other. Ptosis is usually caused by stretching or thinning of the tendon between the muscle that normally raises the eyelid and the eyelid itself. With stretching or thinning, the muscle that normally raises the eyelid has to work harder to lift it. This leads to symptoms of eyelid and forehead muscle fatigue and eyelid heaviness. Other less common causes of ptosis are nerve and muscle damage from any cause, various types of eyelid surgery, infection, muscle weakness, systemic diseases such as stroke and tumors behind the eye, myasthenia, hypertension, thyroid disorders and diabetes. You must get it examined by ophthalmologist to know causative factor and managed accordingly.