Contact lenses material: what are contacts made of?
Contact lenses are produced in a variety of different materials in order to guarantee the comfort, breathability and lasting moisture of the lens. Generally, the composition of the contact lenses is something that you will decide together with your eye doctor in order to provide for the best possible corrections to your specific needs. In any case, it doesn't hurt to do your homework and find out exactly what is used to make up those little pliable lenses.
A list of contact lenses material
Each of the different contact lenses types, such as hard contact lenses vs soft contact lenses, are made up of a different mix of materials.
Soft contact lenses, the most popular lenses on the market today, are made of flexible, water-containing plastics called hydrogels, which are porous and allow for the free flow of oxygen to the corneas. Their water-absorbent characteristic means that, by weight, these contact lenses can be made up of anywhere between 40 and 70 percent water. Depending on the brand, the hydrogel contact lenses have different water content and lens thickness. Generally, hydrogel lenses that have a low water content are thinner than soft lenses that have a high water content.
To prevent buildup of protein deposits on the contact lens, hydrogels may also be charged as ionic or non-ionic. Ionic hydrogel contacts are negatively charged, attracting positively charged proteins, while non-ionic hydrogels are treated to reduce negative charge and prevent protein deposits. Your doctor will be able to tell you which type of these lenses works best for your eyes.
Unlike soft lenses, hard contact lenses are not composed primarily of hydrogels and water. Until around 50 years ago, hard contact lenses were made up of a hard, inflexible plastic material. However, since these lenses do not allow for oxygen to flow to the eye, causing discomfort for the wearer after extended periods of use, they were replaced with contact lenses made from a plastic material that allows gas permeate lenses (fluorine silicone acrylate) , due to microscopic pores that oxygen flows through to reach the corneas.
The rigidity of these lenses and lack of water provides for superior clarity in vision correction than soft lenses, however hydrogel soft lenses are still often the material of choice due to their comfort.
Please note, customers are not required to know the specifics regarding different contact lens materials to order their contacts - you can determine the type of contact lens that best fits your eye together with your OD, who will prescribe the right material accordingly.
Hydrogel vs silicone hydrogel lenses
There are two types of hydrogels, standard hydrogels and silicone hydrogels. Both hydrogel and silicone hydrogel lenses are made of a porous, absorbent plastic material, which is what makes the soft lenses flexible when hydrated, but becomes brittle when it dries out. The key difference between them is that silicone hydrogel lenses allow for greater flow of oxygen to pass through the lens to the cornea than regular hydrogel contact lenses. Greater flow of oxygen to the eyes helps to lower the risk of eye infection.
What is the best material for contact lenses?
The best contact lens material for you is the material that provides you with the clearest vision and that is most comfortable for you. Keep in mind the pros and cons of each of the different kinds of contact lens materials and check with your eye doctor to see what options work best for you , order your contact lenses online and have them shipped right to your door!