There are three kinds of contact lenses: soft contacts, gas-permeable contacts, or hybrid contacts. Soft contacts are the most common type and are also called silicone hydrogel lenses. Gas permeable lenses are rigid lenses that allow oxygen to pass through. Meanwhile, hybrid lenses are a combination of soft lenses and rigid gas –permeable lenses. Because of these differences, the manufacturing process varies greatly, as well.
How To Make Soft Contact Lenses
Plastic polymers called hydrogels are used to make soft contact lenses. This kind of material can absorb a lot of water and hence are soft and pliable without affecting their optical capabilities. Soft contact lenses are made using a highly-specialized lathe that cuts the lenses perfectly and is formed using an injection-molding process.
In the lathe-cutting process, the non-hydrated (dry) disks of soft contacts are individually placed on moving shafts and are formed using precise computer-controlled cutting tools. The front and the back portion of the contact lens are created using the cutting tool, and then the lens is removed from the mold and then hydrated. This softens the lenses, and afterward, these are inspected for quality. With the manufacturing process controlled by computers, it can take only a few minutes to make a soft lathe-cut contact lens.
Another process that is used to make soft contact lenses is by injection molding, where the material of the soft contact is heated until this melts. Afterward, it will be pressure-injected to molds, which are precisely designed by a computer. The lens is cooled quickly and removed from the mold. The lenses will have a rough appearance when these cool down, so these are polished to become smooth. The polished lenses are hydrated to soften them. The injection molding process to make soft contacts is faster and is cheaper compared to the lathe-cut process.
Colored lenses are usually soft contact lenses to enhance the wearer’s comfort. The TTdeye brown contacts are super natural; you can hardly tell that a person is wearing them. These are made of soft material that feels and looks very natural to the wearer.
How To Make Gas-Permeable Contact Lenses
Rigid gas-permeable contact lenses are made of oxygen-permeable plastic polymers that have fluorine and silicone. This kind of lens contains very little water and, therefore, stiff over the eye. This is more expensive because each lens is custom-made according to the specifications of a doctor.
A computer-controlled lathe is used to cut rigid gas-permeable lenses similar to how lathe-cut soft contact lenses are made. These lenses are shipped in a dry container, and before these are dispensed, the prescribing eye doctor will soak this in a specialized contact lenses solution made for gas-permeable lenses. This contact lenses solution will condition the surface of the lens so it can be more comfortable to wear.
How To Make Hybrid Contact Lenses
The center of hybrid contact lenses is made of rigid gas-permeable material, and surrounding this is a peripheral fitting area made of soft contact material. The same lathe-cut process is used to create hybrid contact lenses. However, the plastic discs have a gas-permeable center. After forming this center part of the contact lens, the non-hydrated soft lens material is added to surround the gas-permeable center.
The two different materials won’t separate as you wear them because a unique technology binding process is used to prevent the movement of the materials. With hybrid contact lenses, you can wear your prescription longer without straining your eyes and drying them. Hybrid contact lenses are usually prescription lenses and can only be purchased with the help of an eye doctor.
Cleaning and maintenance of soft contacts, rigid gas-permeable contacts, and hybrid contacts are almost the same. Talk to your doctor about the type of contact lens that’s right for you.