Snellen Scale

Visual acuity is typically measured using the Snellen Scale.

A Snellen test usually consists of a number of rows of letters which get smaller as you read down the chart.

On the Snellen scale, normal visual acuity is called 6/6, which corresponds to the bottom or second bottom line of the chart.

If you can only read the top line of the chart then this should be written as 6/60. This means you can see at 6 metres what someone with standard vision could see from 60 metres away.

The first number of your score corresponds to how far away you are reading the chart (6 metres).

The second number corresponds to the number of lines that you are able to read on the chart. The biggest letters, on the top line correspond to 60 and the bottom line is usually 6.