Sports and Kinetic Visual Acuity

Abstract

Kinetic vision acuity (KVA) is an index developed in Japan that refers to the capacity to recognize a moving object that moves back and forth against the observer. This review outlines the history of KVA and studies on KVA conducted at the Faculty of Health and Sports Science of Juntendo University, i.e. characteristics of KVA in athletes, factors associated with KVA, sports and age-dependent decline of KVA, and effects of docosahexaenoic acid (DHA) and astaxanthin on KVA. KVA was defined in the early 1960s, and the measurement device was invented in 1968. Studies at the Faculty of Health and Sports Science began in the 1990s. In track-and-field athletics and skeleton, a winter downhill event, higher-ranked athletes had higher KVA than lower-ranked athletes. Although KVA cannot be predicted from static visual acuity or reaction time, a significant correlation was found between KVA and the peak latency of visual-evoked potentials. KVA could not be improved by training and did not change between age of 8 and 17 years. In contrast, habitual practice in kendo may inhibit the age-dependent decline in KVA. DHA may also improve KVA in subjects with low KVA; however, astaxanthin did not improve KVA.

Keywords: athletics; dynamic visual acuity; kinetic vision acuity.

Figure 1

Kinetic visual acuity tester AS-4Fα (Kowa, Nagoya, Japan)

Figure 2

Schema to measure kinetic visual acuity. A Landolt ring is approaching from front at a constant speed. The observer discerns the direction of the break as early (far) as possible. This ability is measured as kinetic visual acuity.