Hits and myths: Will reading in bad light ruin your eyesight?
As children, many of us were warned not to read in low light - for example, under our bedcovers with a flashlight - because it would damage our eyesight in the long term.
No
As children, many of us were warned not to read in low light - for example, under our bedcovers with a flashlight - because it would damage our eyesight in the long term.
This belief is so widely accepted that even some health care professionals do not question it. But this idea is nothing more than a medical myth, and there is no strong evidence to support it.
The fact is, nature has its way of helping us navigate through dim lighting, and our eyes are designed to adjust to variations in light level.
When light is scarce, our iris muscles relax and our pupils dilate to take in more light onto our retinas, whereas in bright light, our pupils contract to minimise the amount entering our eyes.
Our retinas - networks of nerves that sit at the back of the eyes - contain light-sensitive cells called rods and cones. The rod cells help us to see when there is very little light present, while the cones help us with colour vision and detail in a well-lit situation.
When light hits our retinas, chemical signals are generated by the rods and cones and are then sent to the brain via the optic nerve.