What connection is there between glaucoma cataracts and diabetes as they have similar symptoms?

Eye exam needed. All can impact vision. All involve different parts of yhe eye (cataract is change to lens, glaucoma involves changes to the optic nerve, and diabtes can change the retina and blood vessels). A complete eye exam is needed to determine if these are present.
It depends. Glaucoma is a disease of the optic nerve, while cataracts affect the lens of the eye. Diabetes can affect multiple parts of the eye. Poorly controlled diabetes can result in early cataracts. There may be a higher risk of glaucoma development from diabetes, but that connection is not as clear cut.