The effect of retinal defocus on golf putting.

The purpose of this experiment was to determine the effect of type and magnitude of retinal defocus on golf putting accuracy, and on the related eye, head, and putter movements. Eye, head, and putter movements were assessed objectively along with putting accuracy in 16 young adult, visually normal inexperienced golfers during a fixed 9-foot golf putt. Convex spherical (+0.50 D, +1.00 D, +1.50 D, +2.00 D, +10.00 D) and cylindrical (+1.00 D x 90, +2.00 D x 90) lenses were added binocularly to create various types and magnitudes of retinal defocus. Putting accuracy was significantly reduced only under the highest spherical blur lens condition (+10.00 D). No significant differences were found between any other lens conditions for eye, head or putter movements. Small amounts of spherical and astigmatic retinal defocus had a minimal impact on overall golf putting performance, except for putting accuracy under the highest blur condition. This is consistent with the findings of related studies. For a fixed putting distance, factors other than quality of the retinal image, such as blur adaptation and motor learning, appeared to be sufficient to maintain a high level of motor performance.