Welcome to the fascinating world of contact lenses! As a beginner, it’s essential to understand the diverse options available. In this article, we will explore the common types of contact lenses and their unique benefits.
By the end, you’ll have a good understanding of the different types of contact lenses and be better equipped to make an informed decision about which option suits your needs best.
Soft Contact Lenses
These are contact lenses made up of a soft, pliable hydrophilic plastic like silicone hydrogel. These lenses are manufactured mostly as disposable pairs. Depending upon the type of contact with the eyes, they are again of the following types:
- Daily contact lenses
These are contact lenses that people wear in the morning and dispose of before going to bed at night. Daily contact lenses should not be worn at night, as they can cause serious complications for the eyes.
These contacts are great options for people wearing contacts as opportunists, e.g., at parties, wedding ceremonies, etc.
The benefits of wearing these lenses are that they are cost-effective, they do not need a solution to clean the contacts, a fresh pair of contacts reduces eye allergies and infections, and they are safe and convenient.
- Weekly or monthly disposable contact lenses
Weekly or monthly disposable lenses need to be replaced on a weekly, every fortnight, or monthly basis. These lenses need to be soaked in a contact lens solution every nightand also need good hygiene maintenance.
These lenses are suitable for correcting refractive errors like myopia, hypermetropia, presbyopia, combinations of any of them, and astigmatism. These lenses should not be worn overnight. If you do not wish to opt for daily-wear contact lenses, then these contact lenses are a suitable option.
These lenses are useful for daily use at an affordable price for a longer period of time. These lenses are considered less hygienic when compared to daily-wear contact lenses.
- Extended-wear contact lenses
These contact lenses can be worn overnight for a minimum of six to thirty days, and they do not need to be kept in contact lens solution. These lenses are convenient to use, relatively cheaper, and gas permeable.
Before wearing these lenses, the wearer should be examined for tolerance to them at night. In addition, these lenses can be potential reservoirs for infective organisms and thus can lead to corneal infections and blindness if untreated. It is mandatory to give the eyes at least one night’s rest before scheduled use of another pair of these lenses.
Hard Contact Lenses
- Rigid Gas Permeable (RGP) Lenses
RGP lenses are a type of hard contact lens that allows oxygen to reach the cornea while in use. These lenses can be worn overnight and can be used for a long period of time (2–3 years).
These lenses are suited for the correction of astigmatism and keratoconus. RGP lenses have distinct advantages: they retain their shape during eye blinking, they provide sharper vision, they have longer durability, and of course, they allow the flow of oxygen through the lens. When compared to other lenses, these lenses are expensive and not comfortable for nighttime wear.
- PMMA Lenses
These lenses were the first hard contact lens ever made, also known as conventional contact lenses. These are made up of polymethylmethacrylate (PMMA), a stiff, plexiglass-type plastic. These lenses are worn for a period of 8–16 hours.
These lenses have excellent optics, are durable and cheap, and provide an extra layer of eye safety when in use. These lenses are a bit rigid, so flexing them can be a problem; they are not gas permeable; they cannot be worn at night; they are least comfortable to wear; and prolonged wear of these hard PMMA lenses can lead to contact lens overwear syndrome. Some people complain of blurry vision with glasses after using these contacts, also known as spectacle blur.
Other Types of Contact Lenses
- Bifocal contact lenses
These contact lenses correct both near and distant vision problems, and recently they have gained popularity among the elders.
- Multifocal lenses
Prescribed for patients who do not want to wear two pairs of prescription glasses.
- Toric contact lenses
Toric contact lenses are customized lenses that correct astigmatism.
- Bandage lenses
These soft contact lenses are used for corneal infections and impending corneal perforations.
- Transition contact lenses
They change color when exposed to UV light and provide a “sunglasses” effect.
Special Types of Contact Lenses
There are additional contact lens types that people may use to enhance eye color, correct special vision problems, or even treat eye diseases.
- Hybrid contact lenses
The centre is RGP, and the periphery is soft in this type of contact. This design is intended for people with irregular corneas. This is a newer type of contact lens, so very few options are available on the market.
- Orthokeratology (Ortho-K)
Orthokeratology, or Ortho-K, uses specially designed hard contact lenses to change the shape of the cornea. This contact lens temporarily corrects vision and is mainly used by nearsighted patients.
Ortho-K lenses are most often prescribed to be worn while sleeping. They are usually removed in the morning and not worn during the day.
- Scleral
This is a hard or RGP lens; these lenses rest on the sclera and are useful to treat damaged corneas and severe dry eye conditions. These lens wearers should follow the instructions given by the eye care providers for proper wear and care.
- Decorative
These lenses enhance or change the color of the eye; they can be purely used for cosmetic or aesthetic purposes or to correct refractive errors with better cosmesis. The wearers should follow the prescription and instructions from the eye care provider regarding maintenance and use.