I see what you did there

Not all visually impaired people are 100% blind. Many can see a small amount, but are much more comfortable using Braille and other aides.

I know a little bit about blindness as I'm blind in one eye but since my eye was completely destroyed it doesn't function.

According to the story the larger buttons are a contact of the person's choice they can call, the phone is basic and cheap its 3d printed and only does voice calls. Here is the story http://mashable.com/2014/05/19/braille-phone-own-fone/