Nonblind

Nonblind is an English adjective formed by adding the prefix non- to blind. It has two broad senses. In everyday and clinical language, it can describe a person who is not blind and has usable vision. In many contexts, however, more precise terms such as sighted or visually unimpaired are preferred. The word is relatively uncommon in modern ophthalmology and disability literature, where standardized terms are favored to describe a person’s level of visual function or legal status.

In medical research, nonblind (also called unblinded) refers to a study design in which participants, investigators, or both know which treatment is being administered. This contrasts with blinded, single-blind, or double-blind designs. Nonblind or open-label trials are chosen when blinding is impractical or unethical, or to assess real-world effectiveness and safety. Researchers acknowledge that lack of blinding can introduce biases in outcome assessment and reporting.

Etymology and usage notes: The term is a straightforward construction from “non-” and “blind” and is not common in everyday speech. In scientific writing, “unblinded” or “open-label” are often preferred, while for vision status “sighted” or “visually unimpaired” are more typical than “nonblind.”