Contact lenses are divided into two main categories: soft and rigid gas permeable. They can be classified as

• Soft Contact Lenses
• RGP Contact Lenses
• Bifocal Contact Lenses
• Toric Contact Lenses
• Corneal Reshaping Treatment
• with Ortho-K
• Kerasoft Contact Lenses for
• Keratoconus
• Boston Scleral Lenses

Soft Contact Lenses

Soft contact lenses are made of a soft polymer plastic material combined with a percentage of water. Water allows oxygen to pass through the contact lens material and increases comfort. Many soft contact lenses also provide UV protection. Soft contact lenses are more comfortable than rigid gas permeable contact lenses when first inserted into the eye.

Many soft contact lenses are disposable and can be thrown away after a short period of use. Being able to have a fresh pair of soft contact lenses means less chance of infection, less cleaning, and more comfort, especially for people whose eyes naturally produce more protein which leaves deposits on the contact lenses. Other soft contact lenses are worn on a yearly basis and are not disposable.

While most people choose soft contact lenses because of their benefits, there are also some disadvantages. Soft contact lenses easily absorb pollutants like lotion or soap from your hands, which can irritate your eyes. Soft contact lenses are also more fragile than hard contact lenses and can rip or tear easily.

The most recent types of soft contact lenses are:

• Daily Disposables. These soft contact lenses are only worn for one day and then thrown away. The benefits include not having to clean your contact lenses on a regular basis, convenient replacement schedule, and reduction of dry eye and irritation related to contact solutions. If you are an allergy sufferer, these are the contact lenses for you.
• Silicone Extended Wear Disposables. These soft contact lenses are made with a new silicone hydrogel material that can be worn for up to 30 nights and days. The new material also prevents deposit build up and reduces dry eye irritation. However, it is safer to wear contact lenses during the day and remove and give eyes a rest at night.
• High-Definition Disposable Contact Lenses. These soft contact lenses are replaced monthly. The high-definition lenses provide a clearer and sharper vision, especially at night, and are designed to reduce halos and glares.
• Colored Soft Contact Lenses They’re hip and they’re fun, but colored contact lenses can also be quite practical for some. There are four types of colored contact lenses, each offering a slightly different benefit:
• Visibility tint. These colored contact lenses are lightly tinted so you can find your lens if you drop it. Visibility tints don’t affect the color of your eyes.
• Enhancement tint. These colored contact lenses have a translucent tint that’s meant to enhance your natural eye color. Enhancement tints are slightly darker than a visibility tint.
• Color tint. Darker, opaque tints that change the color of your eyes. Color tints come in a wide array of specialty colors, including amethyst, violet, and green.
• Light-filtering tint. These colored contact lenses are designed for athletes and sports fans. They enhance certain colors and mute other colors. For instance, contact lenses for tennis players would enhance optic yellow, the color of tennis balls.

Remember, colored contact lenses are a medical device just like clear contact lenses. Never share colored contacts lenses with anyone. Clean and care for them just as you would any prescription contact lens.

Rigid Gas Permeable Contact Lenses

• More rigid than soft contact lenses and therefore more durable.
• Made with silicone polymers, allowing oxygen to circulate to the cornea of the eye.
• Compared to soft contact lenses, rigid gas permeable contacts maintain their shape and offer clearer vision for some types of corrections.
• They are also easy to take care of and are extremely durable.
• The amount of time needed to adjust to rigid gas permeable contact lenses is longer than with soft contact lenses.
• To achieve maximum comfort, a rigid gas permeable contact lens should be worn every day.
• Rigid gas permeable and soft contacts are available as extended wear options.

These contacts may be worn overnight.

Bifocal Contact Lenses

Bifocal contact lenses are designed to give good vision to people who have presbyopia. Presbyopia is the age-related change that affects the natural lens in the eye. Contact lens options for presbyopia include bifocal and monovision designs. Monovision and bifocal designs come as both soft and rigid gas permeable lenses.

A bifocal contact lens design has both the distance prescription and near prescription in one lens. Wearing monovision contact lenses means in one eye you wear the distance prescription while in the other eye you wear the near prescription.

Contact lens wearers also have the option of wearing reading glasses over distance contact lenses. This combination allows for excellent distance and near vision. Glasses can also be prescribed over any of the above combinations to enhance vision as needed.

There are many bifocal contact lens options. A professional fitting and evaluation is necessary to determine which bifocal design will suit your needs.

Toric Contact Lenses

Toric contact lenses are special lenses for people with astigmatism. These lenses are made from the same material as other contact lenses and come in soft or rigid gas permeable forms. Like bifocal lenses, toric lenses have two powers, one for the astigmatism and another for nearsightedness or farsightedness. There is also a mechanism to keep the contact lens relatively stable on the eye when you blink or look around.

Corneal Reshaping Treatment with Ortho-K

Some contact lenses can be used to reshape the cornea and ultimately improve vision. It’s called orthokeratology (ortho-k) and has been practiced for years by some doctors. It has received FDA approval for overnight use which has expanded its appeal. It is potentially beneficial for people of any age who are nearsighted. Ortho-k may be most effective in those with more mild nearsightedness.

With the availability of laser vision correction procedures and many occupations (military and airline aviation) now allowing laser corrected vision, corneal reshaping by contact lens is not currently used as often.

Kerasoft Contact lenses for Keratoconus

KeraSoft is a range of soft and silicone hydrogel contact lenses designed to manage the condition of irregular corneas including keratoconus. They are marketed as an alternative to rigid gas-permeable lenses, offering improved comfort and longer wearing times. Ophthalmologists are using the lenses both pre and post-operatively, following cross-linking surgery and as a safer and longer term solution than corneal transplants.

Boston Scleral Contact Lenses

Boston Scleral Contact lenses is used to improve vision and reduce pain and light sensitivity for people suffering from growing number of disorders or injuries to the eye, such as Keratoconus, corneal ectasia, Stevens Johnson syndrome, sjogren syndrome, complications post-LASIK, complications post-corneal transplant etc. Injuries to the eye such as surgical complications, distorted corneal implants, as well as chemical burn injuries can also be treated by Scleral Contact Lenses.

Authored By Dr. Neera Agrawal