The idiots quick guide to visual loss. No offence but the public and most people with visual loss are unsure about what they are really discussing. The majority of people think that blindness is no vision at all, as if your eyes were closed and there was no light or dark.
Complete blindness is relatively rare only about 3% of registered blind people have that much loss. The remaining 97% of blind people have vision but it is highly individual. There are certain main types of visual loss.
Those with macular disease lose central vision the effect is to cause detail blindness, the world becomes unfocused but the individual has navigational vision that enables them to get around relatively easily. This is in marked contrast to the diseases glaucoma and retinitis pigmentosa these are completely different forms of visual loss, they cause a loss of all the peripheral vision with just a small central field of vision. Imagine looking down a Smartie tube, you have good central vision you can see small detail quite well. But you have little idea of what is going on around you, a nightmare if you want to go anywhere. It causes serious mobility problems.
These two forms are the main forms of visual loss they are opposites and the most extreme. There are many variants of these, trauma, stroke and damage due to retinal detachments.