In the Snellen acuity recording of 20/100, what does the number 100 represent?

In the Snellen acuity recording of 20/100, the number 100 indicates the distance in feet at which a person with normal vision can clearly see a particular line on the eye chart. In other words, if a person's vision is recorded as 20/100, it means that what a person with normal vision can see at 100 feet, the individual being tested can only see at 20 feet. The higher the second number, the worse the vision is compared to standard vision. This format helps assess visual acuity and compare an individual's eyesight to the average eyesight of the population.

This understanding of visual acuity is crucial in clinical settings as it helps professionals determine the degree of visual impairment and make appropriate recommendations for treatment or corrective measures.