A Nottingham youth worker is hoping to become the first visually impaired person to walk to the North Pole.
David Shreeves, 32, sets off for the challenge as part of a six-strong team on Saturday.
He has Stargardt's macular degeneration, which causes acute blurring of his central vision though his peripheral sight is not affected.
"I want to show what visually impaired people are capable of achieving," said Mr Shreeves.
Freezing conditions
He hopes to raise money for the Nottinghamshire Royal Society for the Blind from his journey.
The team will face temperatures as low as -35C.
It will be led by renowned Nottinghamshire explorer Mike Thornewill.
Mr Shreeves said he hoped to raise awareness of some of the issues faced by visually impaired people.
"For many it is a "hidden" disability, which only becomes noticeable when you see how a person is affected by it.
"It is often misinterpreted when someone with a vision impairment can't read quickly or asks assistance when looking for something that is within a few yards."