He completed the distance in four hours and four minutes, which was 26 minutes ahead of his target.
'My wife has already done two marathons, and I thought I'd better have a go at catching up, now that I'm 40. We're also expecting a baby this month so I won't have the energy to do this sort of thing for much longer,' he said. 'It was hard work but I'm over the moon to have done it.'
Long collected the money for Fight for Sight. Ciba Vision matched him pound-for-pound on sponsorship money. 'I've been in optics for 17 years, which is long enough to know that Fight for Sight is a charity worth going the extra mile for,' he added.