Spot the deliberate mitsake

In normal reading, you look at the overall shape of the word, not each individual letter. It’s why words written in ALL CAPS are harder to read. For example, the word “juggling” looks completely different in lower case, as shown. Readers usually fix their eyes on the print only a few times on each line, and take in the the words between these points with their peripheral vision. Accuracy decreases the further they stray from the fixation point. Proofreaders have to read more slowly and fix their eyes on almost every word in order to proofread accurately.