With today’s medical advancements, corrective eye wear has developed from simple eye glasses to more complex types of contact lenses that are thin enough to sit right on top of your eyes.

With more advancements over the years, our contact lenses have developed to provide a wide array of specialized features, applications, and design.

These modern types of contact lenses also provide more comfort, safety, and style to your precious eyes.

Generally, there are 5 different types of contact lenses that you should be aware of. And we’ve categorized these lenses according to the materials used to create them.

Learn more about these different types of contact lenses and find out which one you’re using.

1. Soft Lenses

These soft lenses, also known as hydrogel lenses, are made with a gel material that has water stored inside hydrogel plastics. Soft lenses are very slim and flexible so they can easily follow the shape of your eye.

This type of lens is comfortable and easy to wear making it very popular during the late 90’s.

2. Silicone Hydrogel Lenses

These silicone hydrogel lenses are the newer version of the above-mentioned soft lenses. This type of lens has more pores making it more breathable and allows more oxygen to reach the cornea of your eyes.

A study by CooperVision Inc. Pleasanton, CA concludes that silicone hydrogel lenses provide comfort and are safe for the longevity of a patient’s eye health.

The study also conclude that silicone hydrogel lenses are the accepted standard of care in relation to the general types of contact lenses.

3. Gas Permeable Lenses

Gas permeable lenses, also known as RGP or GP lenses, are types of lenses that are harder and less flexible than the previously mentioned lenses. This type of lens looks very similar and actually feels like PMMA lenses.

But, like the silicone hydrogel lenses, this lens has more pores that allows more breathability to your eyes. With a more porous design, the gas permeable lenses are the most comfortable type of hard lens that you can wear.

In 1978, gas permeable lenses were introduced to the public, which replaced the PMMA contact lenses.

Compared to soft lenses, gas permeable lenses can give you a sharper and more definite type of vision. This lens is particularly effective when you have astigmatism.

It will take some time for you to get used to GP lenses. Gas permeable lenses wear better than soft lenses after you get used to them.

4. Hybrid Contact Lenses

These hybrid contact lenses, based from its name, is a cross between soft lenses and gas permeable lenses. Hybrid lenses offer the comfortability of soft lenses mixed with the clear optics of gas permeable lenses.

This type of lens has a rigid center similar to the material in gas permeable lenses, however it has an outer layer that is similar to the silicone hydrogel lenses.

With all the advantages that hybrid lenses offer, it’s a surprise that it’s not very commonly used in the United States of America.

It could be due to it’s slightly higher price and wearability compared to silicone hydrogel lenses.

5. PMMA Lenses

PMMA lenses are created with a material known as polymethyl methacrylate (PMMA). This material is a rigid plastic-like substance that is also used as an alternative for shatterproof windows.

PMMA lenses can provide a very clear visual experience but are not very breathable for your eyes.

With the lack of oxygen supply that your eyes get with this lens, you’ll find a hard time getting used to wearing it.

Also known as hard contact lenses, PMMA lenses are now replaced with a better version called gas permeable lenses (GP).

How long should you wear your contact lenses?

The wearability varies on the different types of contact lenses that you use. When you get yourself some prescription contact lenses, your eye care physician will also guide you through the basics of proper contact lens care.

You’ll learn about how to take care of your contact lenses, how to wear them, and how often to visit your physician.

The guidelines that an eye physician teaches may differ from person to person. This is due to the fact that different types of contact lenses have different wear time.

Yes, some types of contact lenses are designed to be worn for long periods of time, while others are not.

For a deeper understanding, let’s talk about the 3 categories of contact lens wear.

3 categories of contact lens wear

These categories will focus on soft lenses or silicone hydrogel contact lenses which are the most used type of lenses in the United States. Soft lenses are identified according to the following categories.

Daily Wear Contact Lenses

If you have a pair of daily wear lenses, you can wear them all day and take them off at night. These types of lenses should be removed and cleaned at night so they can be safe to use for an entire day.

You can reuse a single pair of daily wear lenses for a long time, depending on the brand. You should ask your eye care physician if your not sure how long yours will last.

Disposable Contact Lenses

Contrary to its name, daily disposable lenses aren’t a one-time wear type of contact lens. This term is used for day-wear lenses that should be replaced every 2 weeks or so.

They’re called disposable lenses because of their short shelf span.

Extended Wear Contact Lenses

Extended wear contact lenses allow you to wear your contacts for long periods of time. You can also wear this type of lens for naps or when you are sleeping.

You should take note that these lenses are FDA approved and are less common than your regular contact lenses.

What happens when you wear your contact lens too long?

As much as we enjoy the aid and style that our contact lenses give us, our contact lenses aren’t made to be worn 24/7.

This is especially true for the regular contact lenses that most of us use on a daily basis.

There are different types of contact lenses, so you should be aware with what type you are using.

Bad things can happen when we don’t follow our eye doctor’s warning and wear our contact lenses for too long.

Since your contact lenses are on the surface of your eyes, prolonged use can irritate your eyes and even block oxygen flow to your cornea.

When this happens, you are prone to the following eye complications:

Corneal Hypoxia

You get hypoxia when your cornea fails to get the right amount of oxygen that it needs. This is one of the most frequent issue that plagues contact lens users all over the world.

Because your contact lens cover most of your eyes, a bad pair or prolonged use could lead to hypoxia. Corneal hypoxia is especially prevalent with extended-wear type of lenses.

Symptoms of corneal hypoxia include the swelling of your cornea, a blurred or hazy vision, and cloudy eyesight. If not treated, hypoxia can lead to severe issues with the cornea.

Eye Infection

Eye infection occurs when your eyes become irritated from viruses, bacteria, or fungi. There are numerous ways that you can get an eye infection, and using contact lenses that are not properly taken cared of can be one.

According to a WebMD article, 90 percent of contact lens users do not follow the ideal hygienic standards for proper contact lens care.

Corneal Ulcer

Most of the time, corneal ulcer is caused by bacterial infection to your eye. This means that some type of bacteria is eroding the parts of your cornea, which can lead to eye damage and vision loss.

In worst cases, corneal ulcer can lead to the loss of your eye.

These are only a few of the countless number of eye conditions that you could get from wearing your contact lens too long. Do you sleep with your contact lenses on?

Maybe you take a nap or two while wearing contact lenses? If you do, and even when you don’t do it very often, you should know that sleeping with your contact lenses on is a very bad habit that you can avoid.

Decorative Contact Lenses

With the rising popularity of contact lenses, it’s no surprise that people are now using it for aesthetic purposes only.

Yes, that’s right. Nowadays, contact lenses aren’t only used for vision correction anymore, they are also used as fashion accessories.

Decorative contact lenses aren’t bad at all, in fact, it can be really fun. However, the danger arises when you get contact lenses that aren’t medically safe or approved by the FDA.

First and foremost, contact lenses should be treated as a medical device, so whether it’s for fashion or for function, you should always get a prescription for your contact lenses.

Decorative lenses that aren’t prescribed by eye professionals can be very harmful to your eyes.

The quality of un-prescribed lenses can be very poor that it can cause cuts and irritation to your eyes, which can lead to severe eye infections.

In a worst case scenario, the pain and damage on your eyes may require surgery, and can even leave some permanent vision damage.

So you should definitely think twice before you purchase some random fashion contact lenses.

However, if you really want decorative lenses that are safe, you can always go to a trusted eye care professional.

They’ll be happy to point out some safe brands for you to enjoy.

References:

Eye care professionals’ perceptions of the benefits of daily disposable silicone hydrogel contact lenses

https://www.ncbi.nlm.nih.gov/pubmed/30878378

Warning Suggested for Contact Lens Solutions

https://www.webmd.com/eye-health/news/20080610/warning-suggested-for-contact-solutions#1

Contact Lens Materials: A Materials Science Perspective

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6356913/