On the show, Adam Kendall portrayed the husband of Mary Ingalls. On the show, he was blind since childhood after he had an accident and hit his head on a rock while fishing. Later in the series, he regains his sight after another accident.
The actor who portrayed Adam Kendall was not blind in real life. The actor, Linwood Boomer, has continued to work in Hollywood, most recently best known as the creator of the popular television show Malcolm in the Middle.
The character Adam Kendall was not based on a real-life person either. In real life, Mary Ingalls never married nor had any children of her own. The relationship with Adam Kendall was completely fictionalized just for the television show.