Understanding Different Types of Contact Lenses

Contact lenses are an awesome choice for anyone who does not want to wear glasses. One of their top advantages is they give you wider visual access. This means they allow an unrestricted central and peripheral view. This also gives you a feeling of normalcy. To understand the different types of contact lenses, here are the basics you need to know.
 

Classifications

There are different classifications of contact lenses. They are based on the following:
 

• Materials
   

• Wearing time
   

• Replacement
   

• Designs
   

Materials

Contact lenses are mainly classified as soft contacts or rigid gas permeable contacts. The soft lenses are made from either hydrogel or silicone hydrogel. They are thin, flexible, and conform to the surface of the eye. The silicone hydrogel lenses are an advanced type of soft contacts. They are more porous, allowing for oxygen to reach the eye.
 

Before there were RGP lenses, there were polymethyl methacrylate (PMMA) lenses. They do not allow for oxygen circulation and are hard to adapt to. Another use of PMMA material is in shatterproof windows. 
 

RGP lenses allow for oxygen to circulate on the cornea. They fit closer to the eye than PMMA lenses and are more comfortable. They also provide sharper and more accurate vision than soft contact lenses. This is especially so for patients with astigmatism.
 

Hybrid lenses consist of an RGP lens in the center and a soft material outer part. They provide more comfort than soft lenses and the sharp vision of RGP lenses. However, they are more difficult to fit and more expensive.
 

Wearing Time

You can either have daily or extended wear lenses. Daily wear lenses are for one day of wear. Discard them nightly. Extended wear lenses are for several days of wear without removal.
 

Replacement

Replacement refers to how often you should discard your contact lenses. The reason you should replace your contacts is to prevent the buildup of lens deposits. It also prevents contamination that increases the risk of eye infections. RGP lenses are more resistant to deposits, so they are not discarded as often as soft lenses.
 

The general classifications by replacement are:
 

• Daily disposable: For single-day wear
   

• Disposable lenses: Wear them for two weeks or less and then discard them
   

• Frequent replacement: For monthly or quarterly use
   

• Traditional/reusable: Wear for six months or longer
   

Designs

Special contact lens designs depend on their purpose. These contact lenses help fit patients with certain conditions. They are comfortable and help enhance vision.
 

Toric contact lenses are a special design made for patients with astigmatism. They have different powers at different points. They also have a feature that allows them to rotate to the perfect angle on the front of the eye.
 

Bifocal and multifocal lenses contain different powers for near and far vision. Sometimes they also correct astigmatism. Spherical contact lenses are the most common. They treat myopia or hyperopia. The lens power is the same throughout the contact.
 

Lastly, there are cosmetic contact lenses designed for special effects, costume-wear, etc. They have color and different designs on the scleral part. They are for use during Halloween or theatrical productions. They also enhance your eye color.

 

If you want to understand more about the different types of contact lenses, contact Grove Eye Care at our offices in Richmond or Midlothian, Virginia. You can call us at (804) 353-3937 or (804) 888-8998 today to schedule an appointment.