This study tested the assumption that vision does not influence judo performance, provided players start with their grip in place. Able-sighted judoka’s competed in practice matches in sighted and blindfolded opponents. The findings show that vision enhances judo performance. This suggests it would be fairer when blinded and partially sighted judoka’s would not compete together. 

In Paralympic judo, athletes with different degrees of vision impairment (VI) compete together based on the assumption that vision does not influence judo performance, as long as judokas start the match with their grip in place. The aim of this research was to test this assumption. To this end, we conducted two studies. In the first we analysed data from two major recent VI judo competitions to compare the relative performance of blind and partially sighted athletes when competing against each other. This revealed that blind judokas win far less medals in VI judo competitions than their partially sighted opponents. In the second study, twenty-four able-sighted players competed in practice matches in sighted and blindfolded conditions. This showed a significant performance advantage for sighted judokas fighting against blindfolded opponents (see Figure below). We conclude that vision enhances judo performance, even when judokas start the match with their grip in place. These findings suggest that it would be desirable to take measures to make VI judo competition fairer to those who are most severely impaired.

Krabben, K.J., van der Kamp, J., & Mann, D.L. (2018). Fight without sight: The contribution of vision to judo performance. Psychology of Sport and Exercise, 37, 157-163. [full text]

Number of successful throws made (A) and points scored (B) by judoka’s in the sighted (against a blindfolded opponent) and blindfolded (against a sighted opponent) conditions.