The first number, 6, represents the distance from which the eye test is performed, usually six metres. The second number tells how far away a person with standard vision could stand and still read the same line on the eye chart.

In simple terms, if someone has 6/9 vision, they need to stand 6 metres away to see what a person with 6/6 vision can clearly read from 9 metres away.

That does not mean the eyesight is poor. It simply means the sharpness of distance vision is a little lower than what is considered normal.

Explaining this, Dr K Subba Rao, senior cataract and refractive surgeon at Maxivision Sri Mahalakshmi Super Speciality Eye Hospitals, Vanathalipuram, Hyderabad, said, “6/9 vision is a term that often creates confusion and assumption of a serious problem among patients. However, it simply indicates that the sharpness of vision is slightly below the standard level which is 6/6. A person can see at 6 metres what someone with normal 6/6 vision can see clearly from 9 metres.”

Many people with 6/9 vision go about their day without noticing anything unusual until they try reading a distant road sign or watching text on a presentation screen.