What could be causing my eyes to be so sensitive to bright light?

Several causes. Many possible causes of what doctors call "photophobia", or excess light sensitivity. Corneal disorders like scarring or inflammation, dry eye, cataract, inflammation inside the eye (iritis) and certain retinal problems all come to mind. A thorough eye examination will help pinpoint the cause. Sometimes, no cause is found and the patient is just labeled "photophobic". Sunglasses will help.