VISUAL VARIABLES
Pre- and post-training data on following parameters were collected from all three groups: Choice Reaction
time and Movement time were measured using the Reaction Timer (Moart, Lafayette Instrument, USA).
The depth perception ability was measured by the Electronic Depth Perception Device (DP-129,
Medicaid Systems, India). In this, the subjects were asked to align the central movable rod with two fixed rods.
Saccadic eye movement protocol was used to measure ocular motility in the horizontal and vertical
planes from two modified Hart charts [27].
Accommodation was measured as the number of letters read in one minute from a near and far chart
kept at a distance of 0.15 m and 6 m respectively.
The tennis players were rated before the training commenced with the help of The National Tennis
Rating Program (NTRP) which is a system of rating amateur tennis players developed by the United States
Tennis Association (USTA). The players were evaluated by the Tennis Performance Evaluation Form
(singles play) Schwartz & Dazet, 1998 [26].