This site is in the middle of a major expansion. It was originally designed as a resource for vision professionals who wanted to better understand how to care for patients with vision impairments. I'm now reworking the site with content for the general public — people with low vision and people who want to know more about low vision. Once that section is complete, I'll rework the section for vision professionals to better integrate with the general public section. Keep checking back to see how it's going, and if you find the content helpful please consider contributing to support the effort.
Almost all forms of eye pathology result in impaired low contrast vision, and always well before they affect high contrast vision. The effect is to take away the subtlety, richness and texture of the scene. I tend to describe it to patients as being like an underexposed or overexposed photo, in that you can generally see what the scene is, but you’d never say it was a good photo.
Note: Impaired contrast sensitivity usually counts as a falls risk. When we’re on uneven ground, the way we can see subtle changes of contour is by detecting subtle shadows. Patients will low vision often can’t detect such subtleties, so uneven areas on surfaces such as footpaths, gravel paths and grass lawns can be invisible to them. The same applies to going down stairs — if the edges aren’t well marked, many patients simply can’t see where one step ends and the next one begins.