First of all, this is a wonderful episode with a lesson in self-pity. Mary is so absorbed in her own loss of sight (and rightfully so), she doesn't even realize Adam too is blind until he tells her.
The exception to this great episode is Laura's terrible acting, and fake crying. I know Michael Landon saw something in "Half-Pint" thus choosing her to play Laura but damn, her acting is hard to watch in this one.