Varifocal glasses give you clear vision at all distances, with no tell-tale visible lines. But because we understand that some people take a bit of time to get used to them, we're giving you a special guarantee. If you can't get on with them, bring them back within 30 days and you can exchange them for either one pair of bifocals or two pairs of single vision glasses (one for reading and one for distance). What's more, we'll refund any price difference.