The eyes are naturally exposed to the environment, with the maintenance done by the eyelids to keep the front face of the eyeball known as the cornea moist. With many people falling victim to vision problems, some opt for a more discrete solution.
Eyeglasses may be quite annoying for some, so they use contact lenses. The problem arises when most contact lenses are worn are impermeable, where moisture and air alike are restricted access to the cornea. This can result in discomfort for the user, and dry, gritty eyes, especially towards the end of the day.
Hard contact lenses were made with polymethyl methacrylate (PMMA), which had great optical properties and was made to be lightweight and shatter-resistant, but were relatively uncomfortable. This problem is alleviated thanks to recent advances in contact lens technology.
Now, with gas permeable lenses, permeable materials such as silicone are used in the fabrication of these types of lenses. It allows oxygen to pass directly through to keep the cornea healthy without having to rely solely on oxygen-containing tears to be pumped under the lens with each blink.
Thanks to their permeable characteristics, these lenses allow can be made larger than PMMA hard contact lenses, and can be fitted closer to the surface of the eye. These design changes make modern gas permeable lenses more comfortable and easier to get used to than old-fashioned hard contacts. Such design changes also have the added benefits of being more securely emplaced on the eye, with the likelihood of displacement being vastly reduced.
Gas permeable lenses also provide better vision, durability, and deposit resistance than either soft or hard contact lenses alike, and can be considered revolutionary in terms of lens technology.