Visual aid has loop with perforated mask panel having staged holes of different sizes and spacings

摘要

The visual aid loop (3) has a perforated mask panel (1) with the holes (2) in adjacent rows having a diameter difference of point two millimetres between point three and three point five millimetres. The spacing (A) between the edges of the adjacent holes is not smaller than the pupil size of the user. The spacing (C,B) between the perorated mask panel and the loop and the text is variable.