All racquet sports including Squash, Badminton, Tennis and its derivatives are based upon hand/eye coordination. It therefore follows that a high standard of visual acuity will be of benefit to the participant.
Excellent visual acuity is useful for accurate shot placement - whether serving in Tennis or Badminton, awareness of the court boundaries can make the difference between an Ace and a double fault! In squash, awareness of the 'tin' and your opponents position will help loop a winning serve right into the corner.
If we can see the target - be it a ball or shuttlecock - more clearly, we are in a better position to follow its flight and trajectory, as well as to assess any spin one's opponent has imparted upon it, and, crucially, react more quickly. Our (largely subconscious) visual processing of these factors then allows us to make the appropriate adjustments in stance and racquet position in order that we may make a (hopefully winning!) return shot.
When considering racquet sports, it is not only visual acuity that is useful. Clinical evidence (Griffiths et al) illustrates the importance of the dominant eye in tennis -
'In players with strongly established right eye & hand dominance, even small amounts of blur in the non-dominant eye will significantly affect their ability to hit the ball'
Depth Perception - Racquet sports require elements of both aiming* and anticipation* and acute positional awareness of oneself and one's opponent in relation to the net or the 'T' in Squash will be beneficial.
Eye Speed and Dynamic Fixation - Squash is the most explosive of the main racquet sports, requiring rapid reactions as the ball is a small, high velocity target in a confined area. Players with faster eyes will therefore manage to follow the ball more accurately.This is also useful in the 'slower' games of Tennis and Badminton where appreciation of spin and slice assist ones approach.
Contrast and Light Sensitivity - Tennis, and to a lesser extent Badminton, is played in a range of different environments and the visual demand will change accordingly depending on the surface, be it Grass, Clay, Astroturf, Hard court or indoors, the player best able to pick up the trajectory of the ball against the background will have the edge.
Equally, a player who is light sensitive may suffer when playing at night under floodlights or indoors, especially when playing Badminton where high, looping shots can easily get 'lost' in the glare of the lights.
(Ed Lyons www.flintandpartners.co.uk)