What diseases can cause permanent blindness?

Usually chronic ds: mainly diabetes and macular degeneration is common outside of childhood blindness, corneal opacities, glaucoma, trachoma, and onchocerciasis. There are other causes that are progressive in nature, and in other countries out of the US it can be cataracts that aren't treated. In the US, it's a reversible cause of blindness if it can have it surgically treated.