A science story: Wearing glasses
By Isobel Green
I first went to the opticians when I was in school because I started to get headaches when staring at the board in lessons. I was prescribed glasses and told to reserve wearing them for when I really needed them, in a classroom.
I ignored this invaluable advice and wore them constantly. Gradually my eyesight declined from a slight short-sighted prescription to a significant one. Eventually, I became dependent on the visual correction.
How do glasses work?
The eye is made up of a lot of structures which light has to pass through for images to be created. Light passes through the front of the eye (the cornea) and into the lens. The lens bends the light to focus it on the light-sensitive tissue at the back of the eye (the retina). This tissue is made up of specialised cells (rod and cone cells) which transform the light into electrical energy so it can be processed by the brain.
When you are short-sighted, your eyeball has often grown longer than normal, causing distant objects to appear blurred. Short-sightedness is often genetic but can have environmental factors, such as regular near work. When our eyes focus on close objects like books or laptop screens, they can sometimes produce a blurred image behind the retina. To correct this, our eye elongates to focus the image on the retina.
This correction is counterproductive. Now when looking at distant objects, the lens bends the light incorrectly so it focuses in front of the retina. Distant objects are consequently perceived to be blurred. The condition only gets worse the more we focus on near objects. It doesn’t bode well for a generation growing up on screens.
Glasses correct the bending of light into the eye. In my case (I’m short-sighted), my glasses have a concave lens; they bend light outwards so it focuses on my retina – not in front of it. This makes my blurry world clear and crisp.
There is an urban myth which states that wearing glasses too much can cause our eyesight to deteriorate. In fact, we develop an intolerance of blurry vision the more we wear glasses because we become conscious of how clearly we can see with them.
How is the prevalence of short-sightedness changing?
Unfortunately, short-sightedness is becoming more prevalent in the UK. British adults spend 4866 hours per year staring at a screen (laptop, phone, TVs or gaming device). This excessive screen time is putting a huge strain on our eyes.
The consequently higher rate of short-sightedness is great news for glasses sellers – frames have a high mark-up (up to 1000%) so there is money to be made. Advertising has complemented the demand boom by promoting glasses as a fashion item; different styles and designs have blossomed in the last decade.
But glasses never used to be trendy. Until recently, glasses were most commonly worn by those who read more books and spent time straining their eyes by focusing on small details. These people were labelled as nerdy and socially awkward, and glasses became their symbol (think of Fogell from Superbad). A social stigma.
In my experience, it is now more common to be complemented or envied for your glasses – so much so they are often worn with non-prescription lenses by those who do not require a visual aid.
How can I protect my eye health?
Many modern incidences of short-sightedness are tied to our daily activities, such as excessive use of screens and close-up work. We need to reduce the amount of time we spend on our phones and take regular breaks if using a laptop for extended periods. An even simpler action to reduce the impact on our eyes is to go outside! Studies have shown a lack of daylight to be a greater risk factor for short-sightedness than close-up work.