Contact lens technology
There are a few basic types of contact lens materials, making up three different classes of lens: soft, rigid gas permeable, and hybrid. There are also a few new materials being used in the latest contact lens technology. Let’s take a look (wink, wink) at what you’re putting in your eyes.
Soft contact lenses
Soft lenses are one of the most popular types of lenses because they’re made of unique materials called hydrogels. Hydrogels are water-loving (hydrophilic) plastics.
Silicone hydrogels
Hydrogel lenses with low water content are thinner than soft lenses with high water content. However, new contact lens technology has introduced silicone hydrogels, which have higher oxygen permeability.
Soft, oxygen-permeable lenses allow air to reach the eyes, making them serviceable for daily, monthly, or continuous wear.
A final feature of hydrogel lenses is their surface charge, which can be either ionic or non-ionic. Ionic hydrogels have a negatively charged surface and can attract positively charged proteins, which can lead to build-up under the lenses. Non-ionic hydrogels are treated to reduce the surface charge and are less prone to attracting deposits.
Soft contact lens cons
- Because Hydrogels take on moisture by absorbing it from their surrounding environment, some soft contact lenses can absorb moisture from your eyes. But, let’s take a look (oops, we did it again) at the pros.
- Soft contact lenses can be more difficult to clean.
Soft contact lens pros
- Soft contact lenses are flexible, comfortable, and inclined to stay in place.
- They’re often the best contact lens choice for active people.
- Thanks to new contact lens technology, many new soft lenses have surface treatments that preserve the water content and prevent drying.
Various brands and types of soft contact lenses offer different water contents and lens thicknesses.
For more info on soft contact lenses, check out this super awesome, super informative post. (Yes, that was a humble brag.)
Rigid gas permeable (RGP) lenses
Unlike soft lenses, rigid gas-permeable lenses don’t rely on their water content to transmit oxygen to the eyes. Instead, the porous design of RPG lenses allows oxygen to reach the cornea. Although they take some getting used to, RPG lenses have some advantages over soft lenses.
Rigid gas permeable con
- Typically, RGP contact lenses are smaller than soft lenses. The edges of RGP lenses extend only to the outer edge of the iris.
Rigid gas permeable pros
- A GP lens with a high Dk rating is more oxygen-permeable than the best soft contacts, making them a healthier option for your eye.
- They are also more durable and easier to clean than soft contacts.
- Because of their rigidity and because their water content doesn’t change, RGP lenses also deliver crisper vision than soft lenses.
Hybrid contact lenses
Hybrid contact lenses, the latest technology in contact lenses, are a combination of soft and rigid GP contact lenses. They have two major pros.
Hybrid contact lens pros
- Because of the combination of their rigid GP center covering the optical zone and soft outer ring of hydrogel contact lens material, they provide visual clarity of rigid contacts with the comfort of soft contacts. Best of both worlds.
- Hybrid contact lenses correct a wide variety of vision problems, including astigmatism, keratoconus, presbyopia, myopia (nearsightedness), and hyperopia (farsightedness). Hybrids can often be worn by people with irregularly shaped corneas.
Contact lens pros summary
Of the various types of contact lenses, they all have a few things in common. All modern contact lens materials are safe, non-toxic, oxygen-permeable (to varying degrees), can treat most vision problems, and are available in tints and bifocals. They also share some of the same disadvantages: most contact lenses need to be cleaned regularly with a special solution. All contacts must be handled carefully, and all require a prescription.
The most obvious advantage of soft hydrogel lenses is their comfort. They require almost no adjustment period. They also conform to your eye, so they stay in place better than RGP lenses. Soft contacts offer several wearing options, including disposable, daily wear, and extended wear types.
The clear advantage of RGP lenses is enhanced vision. The shape and design of RGP contacts allow for crisper, clearer eyesight than soft lenses can offer. They also cost less; a set can last for several years with proper care. They allow more oxygen to reach the cornea and are less prone to bacteria and protein build-up.
So which contact lenses are right for you? Remember, we’ve got you, with 24/7 customer service, if you have any questions. Just check out the bottom of the page for the different ways you can reach out.
Original publish date: 1/24/2020
Updated: 2/15/2023