Almanac: The eye chart 01:48. And now a page from our "Sunday Morning" Almanac, January 18th, 1908, 107 years ago today . . . the day the Dutch ophthalmologist Herman Snellen died at the age of 73.

The basic concept remains the same regardless of platform: You take a read-the-eye-chart test at home, and an eye doctor reviews your results to determine if your current prescription is still OK.

In his famous eye chart, each row represents a different dioptre, which measures the distance you would have to be from the text to read it. Monoyer also inserted his name into the chart.

Trials on 233 people in Kenya, published in JAMA Ophthalmology, showed the phone produced the same results as eye charts. ... But too often people are beyond the reach of even a basic eye exam.

Trials on 233 people in Kenya, published in JAMA Ophthalmology, showed the phone produced the same results as eye charts. ... But too often people are beyond the reach of even a basic eye exam.