Describing an experiment (usually medical) in which some information which might influence the experiment is withheld from two parties. Most commonly, parties in question are the subjects and the administrators and the information which is withheld is the treatment groups of the subjects.

British spelling spelling of color blind

(American spelling) Alternative form of color blind

(British spelling) Alternative form of colour blind

(of a person or animal) Unable to distinguish between two or more primary colors (usually red and green).

The optic condition nyctalopia, the inability to see clearly in faint light, as at night

A blind consisting of overlapping horizontal, flat slats, usually made of metal, vinyl or wood, that can be tilted so as to let in more or less light.

Having the quality of ignoring gender, such as organizations that accept and/or house people together without discriminating on the basis of gender.

A person who is in love can see no faults or imperfections in the person whom they love.

Completely blind.