You're less strong with your eyes closed
You lose strength if you close your eyes during physical exertion, sports scientists at Samford University in the US discovered when they did an experiment involving 27 students. But if you are used to doing the movement then the reduction as a result of sight loss is negligible. Study The researchers got the students to do leg press exercises on two occasions, using 60 percent of the weight at which they could just manage 1 rep. On one occasion the students were blindfolded once they had got onto the machine, on the other occasion they weren't. Results The lack of vision reduced the power the subjects were able to develop - the speed with which they could push the weight away from themselves - by 6 percent. In men and women who trained with weights in the gym twice a week or more, the loss of power due to loss of sight [white bar] was negligibly small. The blindfold reduced power by a statistically insignificant 1.1 percent. In inexperienced test subjects, the blindfold reduced th...