Many store bought reading glasses are not made or labeled correctly.
A recent investigation done by David Elliott and Alison Green, and published in the Optometry and Vision Science journal of the American Academy of Optometry found that 48% of the 322 reading glasses that they tested were wrong. That means 1 out of every 2 pairs sold over-the-counter is wrong and can hurt your eyes.
The main problems with these readers are:
- Wrong power, or different power between the eyes. Some lenses were not even near the power they claimed to be
- Poor optical quality (like a disposable camera lens compared to a good quality camera lens)
- Induced prism, meaning that the lens may move the image up, down, or sideways
It is safest for your eyes to wear optical-quality prescription lenses that have been custom made for you. Otherwise, you are looking through a slightly distorted lens, that most likely isn’t the right power for you, and the optical center isn’t right for the distance between your eyes (so you’ll have to turn your eyes inwards and look cross-eyed, or outwards to look through the readers). Most people have a small amount of astigmatism, or an imbalance between their eyes, so to see your clearest, and have your eyes focusing on the same plane while you study or work on the computer or at your desk, you need a pair that is made from an eye exam where the doctor has measured your eyes.
Wearing the wrong prescription, or poor quality lenses affects your productivity and comfort while reading.