the condition of a drooping eyelid is called Ptosis. it can be given by different conditions not always chronic, it's possible that it will heal spontaneously.
do you remember when it started? how long ago and did you have any other symptoms preceding it?
ask someone in your family to test you with a simple neurological test, the Romberg's test. it will take a minute: stand up straight with your feet joined together toe to toe, lean your arms forward palms up, look straight forward then close your eyes. if you can't stand still, you wobble, the test is positive. often its related with conditions affecting the optical nerves. look it up on youtube to see how it's done.
a full eye examination also is required you might have had a slight loss of vision or visual field on that eye that you haven't noticed.
The eyelid is controlled by the third cranial nerve, and the drooping is commonly due to a so-called "palsy" of that nerve. Diabetes is the most common etiology, although viral (or bacterial) infections can also be the cause. I would get an hba1c test. Usually the condition persists for a few months and then mysteriously disappears. There is a specialty called opthamalogical neurologist. Sometimes the palsy continues and the eye becomes "frozen" in position, causing double-vision, but this usually resolves on it's own. There are one of two serious neurological diseases that are possible, but unlikely. I wouldn't worry too much, but talk to your mom about making an appointment to have it evaluated. They might want to take an MRI.
its the way you are you will be fine nobody is perfect
It could be a very mild version of Bell's Palsy. You should ask your parents to take you to talk to your doctor about it. It may seem trivial, and it probably is, but it could also be an early sign of something more significant.