1. From the Laboratory of Experimental Optometry, Department of Optometry and Radiography, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; and the2Department of Physiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania.
2. From the Laboratory of Experimental Optometry, Department of Optometry and Radiography, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; and the