The agency won the £1 million account after a pitch against Euro RSCG Wnek Gosper, Leonardo, Grey Worldwide and Target Direct.
JWT will launch an integrated print and media campaign to coincide with the charity's awareness week in October. Press work will run in national newspapers and consumer magazines, with posters appearing on cross-track sites on the London Underground and in national rail stations.
The appointment follows a variety of project work undertaken for the RNIB by Euro RSCG, which created the charity's current press and poster work, "Peter and "Claire", featuring people talking about life without sight.
JWT's managing director, Ros King, said: "The RNIB is a vital charity and a great brand. We look forward to producing some great work for it to reflect that."
D'Arcy previously handled the account for five years, but parted company in July 2000 after strategic differences.
The incumbent media agency, MediaVest, will continue to handle planning and buying.