This challenge was created by the UK crest maker Badge Freaks. The badge package is available for free download and they sell the crests for £1.00 each. A quarter of the sale price of the crests goes to a UK charity that supports research and families affected by Retinitis pigmentosa.
The badge package can be downloaded here. It contains information and activities on blindness, accessibility, colour blindness, and aids such as braille or seeing eye dogs.