“…Crowding was not defined in the vast majority if the studies assessing this parameter [ 1 , 21 , 22 , 25 , 27 , 28 , 32 , 33 , 35 , 37 , 40 , 44 , 45 , 46 , 47 , 53 , 54 , 55 , 63 , 65 , 66 , 67 , 68 , 69 , 70 , 79 , 80 , 82 , 83 , 88 , 92 , 96 , 98 , 101 , 107 , 108 , 109 , 112 , 113 , 114 , 116 , 117 , 119 , 120 , 121 , 124 , 125 , 132 , 133 ]. The remaining studies used the Irregularity Index (Little, 1975) [ 51 ], the method of Björk [ 87 , 90 , 106 ], overlap...…”