Marcus Welby, M.D. The Light at the Threshold (1969–1976) Online
- Original Title :
- The Light at the Threshold
- Genre :
- TV Episode / Drama
- Year :
- 1969–1976
- Directror :
- Joseph Pevney
- Cast :
- Robert Young,James Brolin,Elena Verdugo
- Writer :
- Paul Schneider,David Victor
- Type :
- TV Episode
- Time :
- 1h
- Rating :
- 8.5/10
A teenage girl suffers from a catastrophic eye condition that could leave her blind. Welby searches for answers while the girl tries to adapt to her situation.
| Episode cast overview: | |||
 | Robert Young | - | Dr. Marcus Welby |
 | James Brolin | - | Dr. Steven Kiley |
 | Elena Verdugo | - | Consuelo Lopez |
 | Carol Lawrence | - | Adele Robbins |
 | Gordon Pinsent | - | Dr. Joseph Xavier |
 | Ryan MacDonald | - | Bill Robbins |
 | Audrey Landers | - | Tracy Robbins |
 | Rodney Allen Rippy | - | Jeffrey (as Rodney Alan Rippy) |
| Amentha Dymally | - | Jeffrey's Mother |
| Richard Laurance Williams | - | Technician |
| Tammi Bula | - | 3rd Schoolmate |
| Anthony Eldridge | - | 2nd Schoolmate |
| Pilar Del Rey | - | Nurse |