The E optotype on the chart had 3 limbs of equal length.A regular geometric progression of optotype sizes and distribution was employed to arrange 14 lines with 4 optotypes on each line.
采用三划等长的E形视,视
大小及排列采用均匀的几何增
,
视
数
4
,
14
,
两
视
变化进
拶而。