Dave Heeley, 49, will begin the 183-mile Eyes of the World challenge next April. Sir Ranulph Fiennes and Dr Mike Stroud, the only two men to have previously completed the feat, will accompany Heeley for the final leg of his challenge at the London Marathon.
Malcolm Carr, Heeley's sighted guide, will accompany him in each marathon, and a member of Guide Dogs staff will act as troubleshooter.
Heeley aims to raise the bulk of the cash through corporate donations. He has already been promised £15,000. He said: "I spoke to Ranulph Fiennes, who told me to eat when I can and sleep if and where I can."
Heeley has set up a <a href=www.justgiving.com/777">website</a> for donations.