Sightless. Having a maximal visual acuity of the better eye, after correction by refractive lenses, of one-tenth normal vision or less (20/200 or less on the Snellen test). Of, relating to, or for sightless persons. Performed or made without the benefit of background information that might prejudice the outcome or result: blind taste tests used in marketing studies. Performed without preparation, experience, or knowledge: made a blind stab at answering the question. Performed by instruments and without the use of sight: blind navigation. Unable or unwilling to perceive or understand: blind to a lover's faults. Not based on reason or evidence; unquestioning: put blind faith in their leaders. Slang Drunk. Lacking reason or purpose: blind fate; blind choice. Difficult to comprehend or see; illegible. Incompletely or illegibly addressed: blind mail. Hidden from sight: a blind seam. Screened from the view of oncoming motorists: a blind driveway. Secret or otherwise undisclosed: a blind item in a military budget. Closed at one end: a blind socket; a blind passage. Having no opening: a blind wall. Botany Failing to produce flowers or fruits: a blind bud. Blind people considered as a group. Used with the: a radio station for reading to the blind. Something, such as a window shade or a Venetian blind, that hinders vision or shuts out light. A shelter for concealing hunters or nature photographers. Something intended to conceal the true nature, especially of an activity; a subterfuge. Without seeing; blindly. Without the aid of visual reference: flew blind through the fog. Without forethought or provision; unawares: entered into the scheme blind.