I have been visually impaired for all my life, but lost a lot of vision at age 35. That is when I lost the ability to read printed material.
So, that was over 40 years ago, and now I have very little useable vision left.
I have used the iPhone for three years without ever seeing the screen. I keep screen curtain on all the time.
I use a lot of text to speech apps and 'Be My Eyes' and AIRA.