Rachel gets Kurt signed up on an online dating site. I think Wes gets Blaine set up. Anyways they meet online and eventually exchange cell numbers. It isn't until Kurt surprises Blaine at Dalton that he finds out Blaine is blind. They stay together and move to New York. In the later chapters they are married and adopt a little girl or used a suragant...can't remember. Blaine also starts to see and when he sees Kurt for the first time he comments that he married a model.