Types of Contact Lenses for Vision Correction

What are Contact Lenses?

Contact lenses are thin, clear plastic disks you wear in your eye to improve your vision. Contacts float on the tear film that covers your cornea. Like eyeglasses, contact lenses correct vision problems caused by refractive errors. A refractive error is when the eye does not refract (bend or focus) light properly into the eye resulting in a blurred image.

Contacts can improve vision for people with these refractive errors:

Myopia
Hyperopia
Astigmatism

Types of Contact Lenses

Hard contact lenses
Soft contact lenses - Disposable Contact Lenses

Monthly Disposable Contact lenses
Fortnightly Disposable Contact Lenses
Daily Disposable Contact Lenses

Coloured Contact Lenses
Other types of contact lenses

Scleral Contact Lenses
Rose K Lenses

1. Hard Contact lenses

Rigid gas permeable (RGP) contact lenses, also known as "hard" contact lenses, are inflexible and do not bend or flex like soft lenses. These type of contact lenses, despite their rigidity, they are designed to allow oxygen permeability, enabling your eyes to breathe. RGP lenses are less likely to accumulate irritating deposits compared to soft lenses, and they can provide sharper vision correction. However, there is a learning curve and adjustment period when wearing RGP lenses, as many individuals initially find them less comfortable than soft lenses. While they do allow oxygen to pass through its much lesser than soft contact lenses.

2. Soft Contact Lenses or Disposable contact lenses

Disposable contact lenses are most likely the lenses your eye care professional will recommend. These lenses refer to those lenses which can be frequently replaced after usage. Disposable contact lenses are available as daily disposable, monthly disposable, quarterly disposable, and yearly disposable.

If they are daily disposable contact lenses, then you can wear them for a day and then use a fresh pair the next day.

Benefits of Daily disposable contact lens:

Daily Disposable lenses are easy to manage without any hassle of cleaning or disinfecting them.
Daily Disposables are also beneficial for traveling purposes when you can easily stock up contact lenses to last the trip

On the other hand, monthly disposable contact lenses can be replaced after using them for up to 29 days. It would help if you used soft contact lens care solutions for cleaning, disinfection, and storing the reusable disposable contact lenses.

Toric contact lenses

Toric lenses are prescribed for patients who require cylindrical correction. In other words, toric lenses are used to treat eye issues such as near-sightedness, farsightedness, and astigmatism. These lenses have different powers in different meridians of the contact lens. Thus, toric lenses have mechanisms for stabilizing the lens (such as prism ballast)and avoid any axial rotation. These types of contact lenses are exceptionally breathable and, therefore, safe for extended usage.

Benefits of Toric lens:

Toric lenses have different focusing or refractive powers on the vertical and horizontal orientations

These contact lenses can be worn for extended periods at a stretch as they have high breathability

They are also available as daily disposable contact lenses

3. Coloured Contact Lenses

Coloured contact lenses are available both in prescription and non-prescription varieties, allowing individuals to enhance or completely change the color of their eyes. Whether you want to subtly enhance your natural eye color or make a bold statement, there are many options to choose from. They can be made of both soft or hard materials. Coloured contact lenses are an exciting option for those looking to refresh their appearance or experiment with their eye color. They are designed to change the color of your iris, providing an artistic flair to your look. Let’s dive deeper into the features, benefits, and considerations of using coloured contact lenses.

Types of Coloured Contact Lenses

Enhancement Tints: These lenses are designed to enhance your natural eye color without completely changing it. They usually come in translucent colors that intensify the existing hue of your eyes, making them appear brighter or more vibrant.
Opaque Tints: Unlike enhancement tints, opaque colored lenses are designed to change your eye color completely. They are ideal for individuals with darker eye colors who wish to achieve a lighter or more striking look.
Costume/FX Lenses: These are specialized lenses often used for cosplay, Halloween, or theatrical performances. They can feature unique designs, patterns, and colors, from zombie eyes to mystical fairy hues.

4. Other types of contact lenses

Scleral Contact Lenses

Rigid gas permeable contacts that extend over a broader portion of the eye to cover the sclera (the white part of your eye). They're usually prescribed to help vision issues caused by corneal abnormalities. To know more click Dr Deepak Garg's article on scleral lenses.

Rose K Lenses

These lenses are used mainly in a condition called Keratoconus. Scleral lenses too can be used for keratoconus however Rose K lenses are much more affordable.

Rose K lenses, a specific brand of specialty contact lenses, are designed primarily for individuals with irregular corneas, such as those with keratoconus. These lenses are unique due to their specially designed shape, which helps to correct vision by providing a more regular surface for light to focus on.

Are Multifocal contact Lenses for You? Here's What You Should Know about bifocal contacts

Many in their early 40s are troubled by the need to wear reading glasses. If they dont want to wear progressive glasses or were contact lens wearers earlier they are extremely bothered by this new need to wear reading glasses.

Multifocal lenses, a type of contact lens may be the answer. These lenses will offer you clear vision for far and near and thus the need for glasses may be avoided in the short term. There are certain limitations as regards availability of certain eye powers and about 20% of our patients who try these lenses are not happy with their near vision. Would you like to give these lenses a try?

Contact Lens Materials

When it comes to selecting contact lenses, the choice of lens material is an important factor to consider. There are five main types of contact lenses based on their material, each with its own unique characteristics:

Soft lenses: Made from hydrogels, a gel-like material containing water, soft lenses are known for their thin and flexible nature. They easily conform to the front surface of the eye, providing a comfortable fit.
Silicone hydrogel lenses: These advanced soft lenses allow for better oxygen flow to the front of the eye. Their high oxygen permeability has made them increasingly popular among contact lens wearers. These lenses can also be worn for the longest period of time.
Gas permeable lenses (GP or RGP lenses): These rigid lenses retain their shape on the eye, making them effective for correcting various refractive errors, including astigmatism. While they may require an adjustment period, most people find them just as comfortable as soft lenses.
Hybrid lenses: Combining the best of both worlds, hybrid lenses have a rigid gas permeable central zone surrounded by a "skirt" of either hydrogel or silicone hydrogel material. This design aims to provide the comfort of soft lenses and the clear optics of GP lenses.
PMMA lenses: Made of a plastic material that lacks oxygen permeability, PMMA lenses resemble gas permeable lenses. However, they have largely been replaced by gas permeable lenses due to their limitations.

To determine the most suitable lens material for your individual needs, it's essential to consult with an eye care professional. They will be able to assess your requirements and recommend the best option for you.

How do I choose my contact lenses?

Choosing the right contact lenses for your needs can seem overwhelming with the wide variety of options available. Here are some factors to consider when making your decision:

Vision Correction Needs: The first step in choosing contact lenses is to determine your vision correction needs. Are you nearsighted, farsighted, or do you have astigmatism? Different types of lenses are designed to correct these specific vision problems.
Lifestyle and Activities: Consider your lifestyle and the activities you engage in regularly. If you lead an active lifestyle or participate in sports, you may benefit from lenses that offer better stability and stay in place during physical activities. On the other hand, if you spend long hours in front of digital screens, you might want to look for lenses that provide enhanced moisture and UV protection.
Comfort: Comfort is crucial when it comes to contact lenses. Soft lenses, especially silicone hydrogel lenses, are known for their exceptional comfort due to their high water content and flexibility. However, some people may find gas permeable lenses more comfortable over time, as they allow more oxygen to reach the eyes.
Duration of Wear: Consider how often you plan to wear your contact lenses. Daily disposable lenses are convenient since they are discarded after each use

Risks of Contact Lens Wear

While contact lenses can be a convenient and effective alternative to glasses, they do come with inherent risks if not properly managed. Awareness of these potential issues is essential for maintaining eye health. Here are some risks associated with contact lens wear:

Infections: One of the most common complications associated with contact lens use is the risk of eye infections. Bacterial and fungal infections can develop, especially if lenses are not cleaned properly or are worn longer than recommended. Keratitis, an infection of the cornea, can be particularly serious and requires prompt medical attention. Risk of infection increases with poor contact lens maintenance habbits
Corneal Ulcers: Also known as microbial keratitis, these painful, open sores on the cornea can result from contact lens wear. They may occur due to bacterial infection, improper lens care, or prolonged wear. Symptoms usually include redness, pain, and sensitivity to light, necessitating immediate consultation with an eye care professional.
Dry Eyes: Prolonged contact lens wear can exacerbate dry eye syndrome. Insufficient moisture can lead to discomfort, redness, and a gritty sensation in the eyes. Choosing lenses designed for dry eyes, or using lubricating eye drops, may help mitigate this issue.
Allergic Reactions: Eye allergies in contact lens wearers is common. Its important to use drops and stop wearing lenses while the symptoms continue.