A Light Bulb Moment – How Does Light Affect Our Vision?
Over the last 200 years, an ever-growing variety of lighting options have been introduced to us. While the first electric lights installed in the UK in 1878 essentially came with just one or two options, heading to your local hardware store today can be overwhelming, to say the least.
We can choose from halogen bulbs, LED, CFL, and even ‘smart’ bulbs – and that’s without considering the minefield of wattage, fittings and design! But while we could spend hours selecting the perfect light bulb for our needs, it is unlikely that any of us ever stop to think about how light can affect our vision.
Bearing all this in mind and considering how much we rely on switching on artificial light these days, it’s worth pondering that there are indeed many different types of light and some are considerably more vision-friendly than others.
In this article, we’ll be taking a deep dive into the various types of light, from low light and digital (blue) light to natural UV light and what effects they can have on our eyes.
What is Light?
Visible light is a type of electromagnetic radiation – in fact, all electromagnetic radiation is light, but we can only see a small portion of it. It travels in straight lines in what we call “waves”, bounces off objects and enters our eyes.
Visible light – the light our eyes can detect – is usually defined as having wavelengths of 380-700 nanometres. Within this spectrum of visible light, there are several different types that can affect our eyes in different ways – and not all of them are good.
Of course, we need light to see the world around us. It allows us to detect objects, colours, and depth. Without it, life would be a lot more difficult. But how does the eye actually process light into the detailed images we see?
Light and Our Eyes
For something so small, our eyes are incredibly impressive organs made up of literally millions of vital components. At the beginning of the process of turning light into images, light bounces off the objects around us and enters the eye through the pupil. Our eye automatically adjusts the width of the pupil to control how much light enters – this is why our pupils dilate in low-light settings.
Light entering the eye is refracted by the lens and focused onto the retina at the back of the eye. From here, cone-shaped cells located on the retina act as receivers turning light into electrical signals that are delivered to the brain through the optic nerve. The retina performs in a very similar way to the film in a camera, processing light into impulses through millions of nerve endings which the brain can process as a detailed image.
Artificial Light: Helpful or Harmful?
We started this article by paying homage to the humble light bulb but, as we mentioned, there are a number of different types of artificial light. In many cases, artificial light is one of the most helpful innovations in history. It allows us to carry out tasks in low-light conditions that at one time would have required candles or gas lamps. But there is also a downside to artificial light – particularly when it comes down to our eye health.
You may have heard the term “blue light”: it is generally used to refer to a type of artificial light that is emitted from computers, phones, and other digital devices. Again, this form of artificial light has undoubtedly helped to make our lives easier. Thanks to our digital devices, we are now more connected than ever before and our work and other tasks can be completed much more conveniently.
However, blue light from digital devices (other sources include LED and fluorescent lighting) can affect our eyes more significantly than natural blue light. This is because, while we all know not to stare directly at the sun, the complete opposite is true of our screens. Unfortunately, this means we are all unwittingly straining our eyes on a daily basis.
The Downside to Convenient Artificial Light
Exposure to blue light can lead to digital eye strain which is associated with discomfort and dryness of the eyes as well as sleep disruption. But this type of artificial light can also have more sinister effects. For example, constant exposure to blue light over longer periods has been linked with damage to the retinal cells and vision problems such as age-related macular degeneration. It may also contribute to the development of cataracts and eye cancer.
If you’re concerned that you may be exposing your eyes to too much blue light, there is a simple solution: invest in a pair of blue light glasses. These kinds of glasses work similarly to your trusty sunglasses, the only exception being that they filter blue light instead of UV rays! Of course, another option is to avoid digital devices altogether – but we appreciate this isn’t really practicable in this day and age.
Natural Light: The Better Option?
All this makes it sound like natural light should always be the preferred option. We have all noticed how it is easier to apply makeup or distinguish paint colours in natural light, for example. We might even prefer reading, cooking or any other everyday task in natural light and swear that our eyesight is better in natural light.
As London Vision Clinic optometrist, Vimal Piparia, points out:
“It’s when the days become shorter and darker that most people begin to realise that their vision is not as good as it used to be. You should also be aware that many large stores and some offices still rely on fluorescent lighting and this is not the best light for reading or computer work.
“When natural sunlight isn’t available, try and use a dedicated reading light instead”, he recommends.
And yet, it is also incredibly important to be aware of the dangers of natural light, too. As we have already established, we humans have it drilled into us from a very young age that staring at the sun is bad news. And even if we didn’t, the discomfort we experience when we do is enough to deter us from doing so again. But, many of us don’t actually realise just how much damage sunlight can do to our eyes.
This is largely due to ultraviolet or “UV” light rays emitted from the sun. This UV radiation can damage our eyes in a similar way to artificial “blue” light. Over-exposure to UV light has also been linked to cataracts, eye cancers, and other eye diseases.
That’s why healthcare professionals will always stress the importance of sunglasses and hats to protect your eyes from the sun. But while most of us may only dust off the trusty shades on particularly bright days, it is beneficial to wear sunglasses all year round – not just in the summertime.
To Sum Up
The fact is, in our modern lives, it is practically impossible to live without either natural or artificial light. Both forms of light carry their advantages and health risks, but if we are responsible, we should all be able to continue heading outdoors on bright days and sheltering inside with a book on dull ones.
If you’re concerned about your eye health, get in touch with one of our friendly clinic coordinators today – they’re always happy to help! Alternatively, if you’re interested in treatment at London Vision Clinic, Book a Consultation below.