A study by researchers in Japan made use of pupillometry to evaluate the effects of the calcium channel blockers cilnidipine (CL) and amlodipine (AM) on changes in autonomic nervous activity induced by isometric exercise in patients with hypertension. The velocity of miosis was found to increase in both the CL and AM groups following handgrip exercise. However, the velocity of mydriasis increased in only the AM group. Velocity slopes of miosis and mydriasis seemed to be smaller in the CL group as compared to the AM group. The low-to-high frequency ratio obtained from pulse wave analysis increased in only the AM group. Therefore, isometric exercise invoked sympathetic activation was suppressed more effectively by CL than AM. The findings are published in Clinical and Experimental Hypertension.