Little House on the Prairie - Season 4 - Eps 21: I'll Be Waving As You Drive Away (1)
Mary falls in love with Seth. When Mary's eyesight starts to get worse, Charles takes her to a specialist. He is devastated when the specialist tells him that Mary will lose her sight. Charles is unable to tell Mary for a while that she is going blind. When Mary does go blind, the whole family suffers.
About Little House on the Prairie

Title: Little House on the Prairie
First Air Date: 1974-09-11
Last Air Date: 1983-03-20
Status: Ended
Rating: 7.936/10 (from 909 votes)
Language: EN
Seasons: 10
Total Episodes: 204
Network: NBC
Genres: Western, Drama, Family
Production Companies: Worldvision Enterprises, Ed Friendly Productions, NBC, NBC Studios
Synopsis
Little House on the Prairie is an American Western drama television series, starring Michael Landon, Melissa Gilbert, and Karen Grassle, about a family living on a farm in Walnut Grove, Minnesota, in the 1870s and 1880s.
Cast

Melissa Gilbert
Laura Ingalls

Dean Butler
Almanzo James Wilder

Karen Grassle
Caroline Ingalls

Katherine MacGregor
Harriet Oleson

Melissa Sue Anderson
Mary Ingalls

Richard Bull
Nels Oleson

Victor French
Mr. Edwards

Jonathan Gilbert
Willie Oleson

Allison Balson
Nancy Oleson

Lindsay Kennedy
Jeb Carter