How coloured contact lenses threaten your sight

29 October 2019

Author: Kate Green

Planning on wearing coloured contacts?


Halloween is very nearly upon us! You’ve no doubt already carefully considered your costume, and might have even laid it out ready for the big day. Whether you’re donning a witch’s hat, devil’s horns, or simply draping yourself in a ghostly white sheet, you need to think about whether or not you’ll be enhancing your outfit with coloured cosmetic contact lenses – and if you are, whether you should be.


Coloured contacts have risen in popularity over recent years, both for occasions like Halloween, as well as for everyday use. Often, coloured contacts are used to add the finishing touch to a makeup look or are worn by people – often young women – wanting to change their appearance for the day. As well as providing colour-changing effects, some forms of the contacts – called circle lenses – can make your irises appear bigger by covering some of the sclera. This, however, is especially dangerous as the edges of the lenses sit on the eye’s surface, a particularly delicate area. They can scratch the surface, potentially allowing infection in, or causing eye injuries.


The UK has attempted to reduce instances of these accidents by regulating the contact lens industry. All contacts – cosmetic or otherwise – must be supplied by a registered optometrist. This is so experts can assess whether or not the contacts will suit your eyes and be sure that they won’t impact your eye health in any way. However, people are getting around this by ordering the lenses online from abroad, where they can’t be regulated. This increases the risk of complications caused by cheap, poorly-made lenses.


Common cosmetic lens issues:


  • Sore, red eyes
  • Swelling
  • Eye infections
  • Scratched cornea
  • Foreign body sensation
  • Watery discharge
  • Dry eyes
  • Heavy metal poisoning
  • Light sensitivity
  • Headaches
  • Eye discomfort
  • Blurred vision
  • Deteriorating visual acuity
  • Hindered vision due to lens covering pupil


These issues are heightened by the lenses fitting poorly in your eyes, wearing them for extended periods, and not following good hygiene protocols. Coloured cosmetic lenses “are only designed to be worn for a couple of hours” – anything longer can encourage bacteria to develop. Failing to wash your hands properly before lens insertion, and allowing the lens to come into contact with water, are just a couple of instances which could lead to sight-threatening consequences. Generally, the advice is to immediately remove your contact lenses if you experience any of the above symptoms. If the discomfort doesn’t improve after a day, visit an eye doctor to ensure that no permanent damage has been caused.


Corneal scratches


The most dangerous complication of coloured lenses is a heightened risk of corneal scratches. As previously mentioned, cosmetic lenses aren’t always produced to the same high standards that vision correcting lenses are. The plastic can be harsher, even sometimes containing toxic metals like mercury and lead. It goes without saying that heavy metals like these have absolutely no benefit for your eyes whatsoever, leaking in your eyes and nervous system, causing all kinds of complications. If you’ve previously had LASIK surgery, scratches to your cornea can be even more risky. They can potentially disrupt the corneal flap which was created to correct your prescription, causing discomfort and affecting your vision.


If you scratch your cornea, you’re essentially opening up a gap for germs and bacteria to enter your eye, increasing your infection risk. This is what can lead to irritated eyes, swelling and discharge – in worst case scenarios ending in damaged vision. Scarred corneas can take months to improve – if they do improve at all – and victims of complications from coloured contact lenses report drooping eyelids and vision damage as well as scarring. Ill-fitting lenses have also been known to create a vacuum on the eye, mimicking the effects of a “suction cup”, and causing corneal abrasions when they are removed. Again, this highlights the importance of ensuring your contacts are fitted and recommended for you by an expert.


Cosmetic lenses impair vision


Normal vision-correcting contact lenses are usually transparent, meaning that there’s nothing on them to get in your line of vision – quite the opposite, in fact, as they actually correct your prescription. With coloured cosmetic lenses, however, your vision is actually sometimes hindered. This is because, to create a good likeness for the iris, the contact lens features lines and dots to create the pattern. These small marks can actually be seen by the wearer because the rest of the lens is translucent. Obviously, these can cause a distraction and actually make tasks like driving more dangerous as your vision is impaired.


The middle of the contact lens tends to be left clear, however the size – unlike your natural pupil – doesn’t change. This means that as your pupil expands and contracts to allow different levels of light in, the contact lens can’t mimic the effects. Again, this can hinder your vision and prevent you from using your peripheral vision when you need it. Worryingly, these effects can also impact your balance and mobility, again, making tasks like driving very risky. It goes without saying that if anything is affecting or impairing your vision, you really shouldn’t be driving or carrying out any tasks which rely on good sight to be done safely.


Preserving your sight on Fright Night


If you’re set on wearing coloured contact lenses this Thursday, there are some steps you can take to make sure you’re keeping things as risk-free as possible. First and foremost, never lend your lenses to anyone and, if they are for one-time use only, ensure that you dispose of them once you have used them. Reusing coloured lenses gives bacteria a chance to enter your eyes, increasing your risk of infection. If the lenses are intended for repeated use, it’s crucial that you disinfect, clean and store them effectively and safely. Guidelines around how long to wear the lenses for vary between anything from “a few hours” to no more than 12 hours. Essentially, if you feel any discomfort, remove them as soon as possible.


Ensure that your hands are clean before insertion, and try not to expose the contacts to water – such as in the shower or a swimming pool – as water-borne bacteria can become trapped behind the lens. This is incredibly dangerous and can threaten your sight with a disease called Acanthamoeba Keratitis. Safer alternatives for enhancing your Halloween costumes include decorative masks and face paints. While the look might be not quite as striking as you were hoping to achieve with cosmetic coloured lenses, you can be sure that your eyes won’t be impacted negatively. And really, what could be scarier this Halloween than losing your sight?

Back to Blog