Your studly, womanizing main man is walking down the school hall, and eyes a gorgeous woman he's never seen before. When he tries to start putting his moves on her, he finds out something.
Or deaf, or has a prosthetic leg, or something like that.
But don't worry, she'll still probably fall for you anyways. Especially with that prosthetic leg...
The Disabled Love Interest is a (usually temporary) Love Interest, most often Inspirationally Disabled. She'll overcome her challenges in the end, and have a steamy kiss while she's at it. Homework question: Why is she usually only temporary? Unfortunate Implications indeed.
Still can be done well, if the love interest isn't played off as Inspirationally Disabled, and if it offers the character growth and maturity.