There are a wide range of visual impairments. I have included some photographic examples here, which simulate some of the more common conditions. They will give you some idea of what the vision of a person with conditions like glaucoma, macular degeneration, etc. can be like.
Following screenshots are of a user getting on a bus in Dublin.
The following shows a Glaucoma visual sample:
A person with glaucoma may experience loss of their peripheral or side vision. In the early stage glaucoma causes a subtle loss of contrast, which can lead to difficulties seeing things around your environment and certainly lead to difficulty using a computer monitor.
This can lead to what is called 'tunnel vision' where the person can still read and do close-up work but has no side vision.
