CHI beat WCRS and Atomic to the business, after the charity met with eight agencies at the chemistry stage.
The agency will begin working with RNIB immediately to create "a galvanising, contemporary platform" for the brand, with the aim of both growing revenues, and developing the brand’s customer engagement.
Sarah Golding, chief executive officer of CHI & Partners, said: "We’re excited to begin working with [RNIB] on a bold creative strategy that will genuinely change attitudes and transform lives, building on RNIB’s history and working towards a positive future for everyone affected by sight loss."
RNIB has previously worked with Arthur London, Good Agency and St Luke’s.
A 2015 campaign for the brand (pictured above) by Good Agency was initially banned by Facebook on the basis that it broke guidlines on the use of language that is "profane, vulgar, threatening or generates high negative feedback". Facebook later reversed the decision and apologised.
Commenting on the decision to appoint CHI, Deborah Auty, group head of marketing and communications at RNIB, said: "More than half of all sight loss is preventable and we’re confident they are the right agency to engage more people in the conversation about eye health and the issues affecting blind people than ever before."