Tinted Eye Level Reading Rulers Two of Celery Tinted Eye Level Reading Rulers Two Of Celery The EYE LEVEL READING RULER is a coloured overlay filter and text highlighter about the size of a six-inch ruler... Our ten colours have been selected to provide the optimum choice between tints while also recognising the areas of the spectrum that are most frequently beneficial. Within that selection, our "five most popular colour" packs reflect the commonest choices from our own statistics. There is no complicated testing procedure: your students (or you, if they're for yourself) will know quickly which colour "works". When you do know what tint(s) you want, you can buy single colour packs from this page, or you can use the order form that comes with the reading rulers to specify the exact mix you require. Narrow (app. 1 cm) strip for highlighting single lines of text.