After using the app 40 times, users with an average age of 51 were able to read two lines lower on an optical chart held 40cm from their face – a reduction in "eye age" from 50.5 to 41.9 years.

This time, the artist adopts eyes of various sizes to replace the traditional "E"s. The icon of eye can be rotated through a control at the backside of it.

True, I no longer wear glasses. But the 20/20 line on the eye chart is blurry. I can make it out only if I squint, and it takes about a minute to read.