The short answerNo. 6/6 vision only means your sharp central distance vision is normal on the day of the test. Serious conditions such as glaucoma, early keratoconus and diabetic retinopathy start without any drop on the chart, and they are only found by a full exam that includes eye pressure, a look at the back of the eye and sometimes a corneal scan.
Problems that start while vision is still 6/6
1. Glaucoma
Glaucoma damages the optic nerve slowly, starting with side vision, so people keep reading 6/6 until late stages. Most types are painless, and the damage does not come back. Measuring eye pressure and examining the nerve is how it is found.
2. Early keratoconus
Early on, vision still reaches 6/6 with glasses, and the only sign may be astigmatism that rises from year to year. It usually appears in the teenage years, and a corneal scan finds it before vision drops. More about keratoconus.
3. Diabetic retinopathy
A person with diabetes can have small bleeds or leaks in the retina with perfectly normal vision. That is why people with diabetes should have the back of the eye checked at least once a year, even without symptoms.
4. A lazy eye on one side
If one eye is weak and the other is 6/6, a child and their parents may notice nothing, because the strong eye covers for it. Each eye must be tested on its own, ideally before a child starts school.
5. Presbyopia
After 40, distance vision can stay 6/6 while reading and phone use become tiring. This is a normal change in the eye's lens and is corrected with reading glasses or other options. About presbyopia.
6. Early cataract
Early on, a patient may read 6/6 in the exam room but complain of glare from headlights at night or faded colours. About cataract.
7. Dry eye
Dry eye can make vision fluctuate through the day, with burning and a gritty feeling, while the chart result is 6/6. About dry eye.
Who needs a full exam even with 6/6 vision?
- People with diabetes: a retina check every year.
- Anyone with a parent, brother or sister who has glaucoma.
- Everyone over 40, as a routine check.
- Children before school, and any child who sits close to the TV or tilts their head.
- Teenagers whose astigmatism keeps rising or who rub their eyes a lot.
- Anyone using steroid eye drops for long periods.
Frequently asked questions
An optician tested me and I got 6/6. Is that enough?
A sight test measures acuity only. A full exam by an ophthalmologist includes eye pressure and a look at the cornea, lens and retina, which is what finds silent disease.
How often should I have my eyes checked?
For a healthy adult under 40 with no symptoms, roughly every two years. After 40, or with diabetes or a family history of glaucoma, every year or as your doctor advises.
Which symptoms need an urgent exam?
Sudden loss of vision, a curtain over your sight, a sudden burst of flashes and floaters, severe pain with redness, or an eye injury. These cannot wait.