Around 4.2 million people in the UK use contact lenses for vision correction, with close to 800 million contacts sold each year.1 People choose contact lenses for various reasons, ranging from lifestyle to the way they look, or due to the convenience they offer. If you are considering contact lenses, it is important to understand how they work when deciding whether they are right for you.
What are contact lenses and how do they work?
Contact lenses, as the name suggests, are small prescription lenses that are worn on the surface of the eyes. They float on a thin film of tears on the cornea (the transparent front portion of the eye). Contact lenses can correct refractive errors such as myopia (short-sightedness), hyperopia (long-sightedness), astigmatism (when your cornea is curved irregularly), and presbyopia (an age-related reading issue). They do so essentially by functioning like glasses, i.e., by bending and focusing light onto the retina, the light-sensitive layer in the back of the eye where images are formed. You can think of them as tiny glasses lenses applied directly to the surface of your eye.
What are the benefits of contact lenses, and are they suitable for me?
Here are some of the advantages of contact lenses:
- They are worn directly on the eye and provide more ‘natural’ vision, without distortion
- They bring the entire field of view into focus without frames blocking the peripheral vision (which is why many athletes wear them)
- There are no reflections of the lens, in the way that occurs with eyeglasses.
- There is no uncomfortable weight on your nose and ears
- Contacts do not fog up with temperature changes or collect precipitation in rain and snow You can wear whichever pair of fashionable sunglasses you fancy (there’s no need for prescription sunglasses)
If you’re thinking about wearing contact lenses, consider their convenience, comfort, and aesthetics, and also take into account your lifestyle and budget. Glasses require very little care and, as they don’t touch your eyes, they don’t increase the risk of eye infections. Glasses are also less expensive than contacts.
However, if appearance is important to you or your lifestyle would be made easier through contact lens use, then they can certainly be a good option. You’ll have to spend a little extra time and effort on the cleaning and care of your contact lenses, although daily disposable contact lenses don’t require much care or any cleaning. With a little practice, it’s very easy to insert and remove contact lenses.
There are different types of contact lenses that offer different levels of comfort, and ‘soft' contact lenses are very comfortable to wear. Of course, they are aesthetically pleasing, and you will be able to participate in all land-based sports and activities without worrying about your glasses getting in the way or falling off.
What are the different types of contact lenses?
Your optician will suggest a type of contact lens that they feel will be best for you. Here’s an overview of the different types available:
Short-sighted contact lenses
People with myopia (short-sightedness) can see objects close to them clearly, but objects that are further away are blurry. When an object is far away, the image that forms in their eye focuses in front of their retina instead of on the retina. This results in blurry distance vision.
Contact lenses for myopia are concave lenses that spread the light that hits the lens, which allows the image to focus on the retina.
Long-sighted contact lenses
People with hyperopia (long-sightedness) can see objects far away from them clearly, but objects that are close to them are blurry. When an object is up close, the image in the eye focuses behind the retina instead of on it, resulting in blurry near vision.
Contact lenses for hyperopia are convex lenses that focus the image exactly on the retina.
Contact lenses for presbyopia
Presbyopia is a normal part of ageing that typically occurs after age 40. It is caused by a loss of elasticity of the natural lens of the eye which makes it difficult to see objects up close. Although the effect is the same (blurry close-up vision), hyperopia is caused by a short eyeball whereas presbyopia is caused by a hard lens.Contact lenses for presbyopia are convex lenses that focus the image onto the retina to provide clear near vision. Multifocal contact lenses (lenses with more than one prescription built into them) can correct myopia, hypermetropia, and presbyopia.
Contact lenses for astigmatism
People with astigmatism have an irregular curvature of the eye that causes blurry vision. This condition can accompany myopia or hyperopia. Contact lenses for astigmatism are called toric contact lenses. They contain a cylindrical curve to compensate for the irregular curvature of the eye. The lens can contain a correction for both short-sightedness/long-sightedness and astigmatism.
Which contact lenses are right for me?
Your choice of contact lenses will depend on your prescription, your lifestyle, and your budget.
Daily disposable contact lenses
Daily disposables are the most comfortable and convenient lenses to use: you simply discard the lens after a single day’s use. There is minimal care and maintenance required and they’re also the safest in terms of eye health. These are ideal for people with a busy lifestyle who need a quick, comfortable, and hassle-free solution. However, the cost may be prohibitive for some people.
Monthly disposable soft contact lenses
These are worn every day for a month and stored overnight in a sterile solution. They require some additional time and effort in cleaning and maintenance. Monthly disposables are ideal for people who use contact lenses every day and are looking for a more cost-effective solution than daily disposables. You can also get twice-monthly disposables which you replace every two weeks.
Toric contact lenses
These are for people who require correction of astigmatism and can include corrections for myopia/hyperopia as well as astigmatism. Toric lenses are available as daily and monthly disposables.
Multifocal contact lenses
People with presbyopia and myopia can benefit from multifocal contact lenses that correct both refractive errors.
Multifocal contacts restore vision at all distances in one easy solution.
Extended wear contact lenses
Extended wear lenses can be worn for up to seven days continuously. There are even some contacts that can be worn for up to 30 days straight. These are ideal for people with active and unpredictable lifestyles or who have very high refractive errors that need vision correction at all times.
UV contact lenses
Some contact lenses provide additional protection to the eyes from the sun’s harmful ultraviolet radiation. These are recommended for people who spend a lot of time outdoors.
Sunglasses should be worn in conjunction with UV contact lenses to fully cover the eyes and surrounding skin.2
1. The Association of British Dispensing Opticians. (no date). ACLM 2016 contact lens statistics. [Online]. Available at: https://www.abdo.org.uk/news/aclm-2016-contact-lens-statistics/ [Accessed 9 November 2019].
2. Acuvue. (no date). UV Blocking Benefits. [Online]. Available at: https://www.acuvue.com/why-contact-lenses/uv-blocking-benefits [Accessed 9 November 2019].