How is your vision? Any difficulty reading or seeing small objects up close or small things in the distance such as street signs or the ticker-tape on the bottom of the TV screen? Has the vision changed at all since you've become more light-sensitive?
Well, it is true that if you have diabetes long enough that you eventually will have some degree of retinopathy; however, for those who keep their diabetes under control (keeping their hemoglobin A1C under 7.0 consistently), the baseline level of retinopathy you may get after 30-40 years usually does not cause problems with the vision.
It sounds as though you have small glasses prescription for distance vision and that when you wear those and when you wear your near vision correction you see well? Is the blurry vision only when you're not wearing these glasses?