Types of contact lenses

Permanent contact lenses

Permanent contact lenses are a type of implantable contact lenses (ICL) called phakic intraocular lenses (PIOLs), and are made of clear, flexible plastic. ICLs are a type of lens that sits inside the eye — in front of the eye’s lens, as opposed to disposable lenses that sit over the surface of the eye. 

Permanent lens surgery may be a good option for people who don’t want to rely on glasses but aren’t suitable for laser eye surgery. Permanent contact lenses are also used for treating high prescriptions or astigmatism (where the cornea, the eye’s transparent outer layer, is shaped irregularly). Note that although these lenses are known as permanent lenses, they are removable.

UV contact lenses

Invisible UV rays aren’t just harmful to your skin but can cause short- and long-term damage to your eyes, too. Excessive exposure of your eyes to the sun can cause sunburn-like inflammation to the cornea, which is the clear, protective outer layer of the eye. This inflammation is known as a condition called photokeratitis. Long-term UV exposure is believed to exacerbate age-related macular degeneration — a condition that causes vision loss in the centre of the visual field — and is also linked to cataracts.⁶ 

To protect your eyes from UV rays, you can wear sunglasses or contact lenses with UV-blocking technology. UV contact lenses contain a UV-blocking ingredient that is incorporated into the material of the lens itself. But while UV contact lenses work very well as a safety measure against the sun’s harmful rays, it’s important to note that contact lenses don’t provide complete UV protection — not all ultraviolet rays can be blocked out with contact lenses alone. 

Smart contact lenses

Smart contact lenses are a new breed of lens, still in development, that can do much more than improve vision. One of the first companies to branch out into smart lens technology was Microsoft. In 2011, the company collaborated on a research project with the University of Washington to design a contact lens with a sensor that was able to monitor the glucose levels of the person wearing it.¹ The technology was aimed at helping people with diabetes monitor their blood sugar levels without the need for a finger-prick test. In 2014, Google unveiled a similar technology, although their project was stopped in 2018. Ghent University has also developed technology that will allow text to be projected onto a contact lens. So in the future, smart contact lens wearers might be able to read text messages from their phones directly across the eyes.²

The global smart contact lenses market is expected to reach USD 2,860.50 million by 2025 while seeing a significant compound annual growth rate of 49.6% from 2019-2025.³ However, there are several challenges that pharmaceutical and tech giants face, including addressing privacy concerns. In addition, the development of smart contact lenses requires ensuring the lens is thin enough to fit over the eye comfortably, the tiny sensors and microelectronics contained within will need to supply enough power to make them work effectively, and they must be able to relay reliable information to help doctors with diagnosis and to improve treatments for patients.⁵

Gas permeable lenses

Gas permeable lenses are rigid lenses - in many ways, they're similar to hard lenses but are porous to oxygen. It can take up to four weeks to get used to wearing gas-permeable lenses.