Hint: Standard ear bud cord is 38"

In response to review entitled "Huh?" who asks How do we know we are 4 feet from the patient?. The standard cord length of your Apple supplied ear buds is 38". But measure yours. 4 ft is cord plus 4 inches Given the fact that this App is free and just for screening this is a handy application.

Dr. OBoogie about EyeChart - Vision Screening