A blindfold is a piece of cloth or material that covers someone's eyes, making it so that they cannot see. It is often used as a way to play games or to prevent someone from seeing something. Full definition
Ask the other group members with blindfolds on where you are now. (myplaytherapypage.com)
Think you're ready to spot basic candlestick patterns with blindfolds on? (babypips.com)
Frize purposely avoids choosing colors for their specific associations or emotive properties, instead relying on chance — even painting while blindfolded in some cases — and seeking a level of neutrality in which no single color dominates his practice or becomes his signature. (pacegallery.com)