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Figure 1　Kinetic visual acuity tester AS-4Fα (Kowa, Nagoya, Japan)the horizontal plane increased from 10 to 170 deg/sec. There was also a significant difference in DVA in subjects with almost the same static visual acuity (SVA)2). A recent review summarizes the characteristics of DVA in comparison with SVA3). In Japan, Kowa (Nagoya, Japan) launched the first DVA-measuring device HI-10 in 1998. The device had been mainly used under the guidance of the Japan Sports Vision Association although it is no longer manufactured and sold.Hagino et al. of Nagoya University began vigorous research on the ability to recognize moving objects in the 1950s4). Suzumura defined KVA as the ability to recognize an object moving back and forth in the distance against the observer4, 5). Suzumura invented a device to measure KVA in 19686). The device, AS-4A, was launched by Kowa (Nagoya, Japan) in 1966 and has been mainly used in Japan as a tool for driving education for automobile drivers. Currently, the AS-4Fα (Figure 1), the successor to the AS-4A (Kowa, Nagoya, Japan), is available, which identifies KVA as the ability to recognize the Landolt ring approaching the observer from 50 m from the front at 30 km/h (Figure 2).To recognize a moving object accurately, it is necessary to quickly catch the object near the central fossa, adjust it, and bring it into focus. Moving objects are usually more difficult to see clearly than stationary ones; therefore, KVA does not exceed SVA. Suzumura has clarified that (1) KVA decreases as the speed of the target increases, (2) individual variability in KVA is large, (3) 388Figure 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.decline in KVA cannot be perceived, and (4) decline in KVA is unrelated to SVA7).DVA is widely used in Europe and the United States, whereas KVA is mainly used in Japan. In PubMed, search results for “dynamic visual acuity” included 349 papers, 266 of which were published in 2001 or later. Meanwhile, search results for “kinetic visual acuity” included 31 papers, only 5 of which were published in 2001 or later (searched on February 2, 2022). The large difference in the number of papers can be attributed to KVA being developed in Japan and many previously published studies being in Japanese.In 1974, Sanderson et al. reported a significant KVA of athletes