Medical Definition of Blind

Blind: 1. Unable to see. Without part or all of the sense of sight.
2. In a clinical trial, not to know the treatment given or received. The participant is not told whether they are in the experimental or control arm of the study. Also called masked.

Source: MedTerms™ Medical Dictionary
https://www.medicinenet.com/script/main/art.asp?articlekey=11044
Last Editorial Review: 7/1/2016