I have been seeing this moving bead of light in the peripheral of my vision in one eye. The bead of light comes from the corner and curves upwards and disappears. Most days this happens once every hour or so but occasionally it could happen once every five to ten minutes. There have been days when it occurred just once or twice as well. I am nearsighted and wear glasses and this happens with or without them on. I normally only see it at night or when it's semi-dark. Have seen it in the day time as well. What could be causing this?

While seeing flashes of light in your peripheral vision are typically related to the gel-like material inside your eye (vitreous) tugging against the retina (the light-sensitive layer of tissue that lines the inside of the eye), your description sounds more like a form of an “entopic phenomenon”. 

This broad term refers to unusual visual symptoms related to the structure of the eye. The bead of light that you noticed may be a form of Scheerer’s Phenomenon, where white blood cells can displace red blood cells in the capillaries (fine branching blood cells), allowing more light through to the retina. This creates the illusion of a light spot moving in your peripheral vision. This is a normal occurrence and not typically related to any serious eye health issues.

However, I recommend visiting your local optometrist to be 100% sure.  Your optometrist will be able to examine your eyes and tell if you do have an eye condition that could also be causing this to happen.
 
If you don’t have an optometrist, you can use OAO’s find-a-doctor tool to locate one near you. 

All the best, 

Dr. Joseph Chan, OD