Whether you are a contact lenses distributor or an individual buyer, you need to know the types and materials of contact lenses before you start this business, as these help you to better go about finding suppliers and selling. Below we will talk to you in detail about the types and materials of lenses that we hope will be helpful to you.
Soft contact lenses
Soft contact lenses are made of plastic, but not the plastic used in garbage bags or paper plates. Instead, soft lenses are made of hydrophilic plastic, which is a particular type of absorbent plastic that stays soft and moist as long as it absorbs a lot of water.
If you wear soft contact lenses, you may have noticed the properties of this plastic. If your lenses dry out, they can become brittle and even break. As long as the plastic remains nice and moist inside your eye or case, it will remain pliable and soft.
In your eyes, this soft flexibility means comfort. When your lenses dry out, your eyes will begin to feel discomfort because they rely on moisture to keep their position and flexibility.
Soft contact lenses are classified by the amount of water they contain. They can be classified as high or low water content.
Soft contact lenses that can be worn for long periods
Most long-wearing contact lenses are made of silicone hydrogel, a material that combines the absorbent plastic of soft lenses with silicone. Adding silicon to the hydrogel plastic keeps the lens moist and allows more oxygen to pass through the contact lens to the eye. This keeps the eyes healthy while using contact lenses. More moisture and oxygen reaching the eyes is why this material is added to long-wearing contact lenses.
Any contact lens needs to be available to the wearer to maintain contact and allow the eyes to breathe and stay moist during the day and night. The addition of silicone to lenses provides this function for optimal eyewear health.
Rigid Contact Lenses
Rigid contact lenses (RGP lenses) are also made of plastic. Unlike plastic, which is manufactured to be soft, rigid lenses transmit oxygen without absorbing water. Instead, RGP lenses have tiny holes that allow oxygen to pass through. Therefore, RGP lenses pass their oxygen permeability independently of their water content. Today, most RGP lenses are made of three main materials: acrylate, silicone, and fluorine.
RGP lenses differ from rigid lenses made mainly of acrylics a few decades ago. These older, rigid lenses were because there was not enough oxygen to get through. Over the years, lens manufacturers added silicon to increase oxygen permeability and eventually fluorine to help keep the lenses moist while still retaining their shape. This shape retention property allows them to be used as a treatment to correct eye problems such as cone corneas (corneal distortion).
Hybrid contact lenses
Although rare, hybrid contact lenses exist that combine the materials of RGP lenses and soft contact lenses. These lenses have a combination of acrylic-silicone fluoroelastomer in the middle of the lens to provide a clear central vision and soft contact lens absorbent hydrogel around the edges to enhance comfort.