Have you ever looked into the wide variety of contact lenses available today? It might be challenging to understand what they are, who they are for, and when to use them. Do you want daily updates? Toric? Monthly? Multifocal? Is it gas permeable? The list could go on and on.
Of course, your eye doctor will advise you on what is best for your eyes, but it’s always a good idea to be aware of the many lenses available. Here’s a quick rundown.
The original form of contact lenses was hard contact lenses. They are composed of PMMA, often known as Plexiglass. Contacts were created from the conventional hard glass before the discovery of PMMA. Because hard lenses have inadequate oxygen flow, very few individuals wear them nowadays. Furthermore, rigid gas permeable glasses are far more comfortable.
Rigid Gas Permeable Lenses (RGP)
Hard contacts are rigid gas permeable lenses. These lenses, made of stiff plastic and flexible silicone, allow more oxygen to reach the eye. RGP contacts are smaller than soft lenses and cover approximately 75% of the cornea. They have virtually taken the place of PMMA contacts.
Soft disposable contact lenses
A novel material known as hydrogel was created in the 1960s. Instead of producing hard lenses, this water-absorbing material produced the first soft lenses. In addition, these soft contacts are disposable rather than lasting a long time. Users can wear them for one day to one month.
The water content of today’s hydrogel contacts ranges from 40 to 80%. The hydrogel used in the lenses might be ionic or non-ionic. Because non-ionic hydrogel soft contacts attract fewer proteins, there is less risk of protein accumulation.
Daily Disposable Contact Lenses vs Daily Wear Contact Lenses
Some individuals confuse daily wear contact lenses with daily disposable contact lenses. Although they are both soft contacts, they are significantly different.
Daily use contacts are worn for up to 18 hours per day. At night, the wearer cleans, sterilises, and stores the lenses. There are various alternative lens replacement regimens for daily wear contacts. These are some examples:
Daily disposable contacts, however, are only suitable for one use. The lenses are inserted in the morning and removed at the end of the day by the wearer. Because these contacts are not intended to be worn again, there are no cleaning or storage instructions.
Disposable Contact Lenses for Extended Wear
Soft contact lenses are sometimes known as extended-wear contacts. However, the user must wear these contacts throughout the day and night for an extended time. For example, some extended-wear contacts can last up to 30 days, while others only last seven.
But why don’t individuals just wear their regular lenses overnight instead of paying for extended-use lenses? Due to low oxygen levels. Daily lenses do not offer enough oxygen to the eye to be worn 24 hours a day.
If you use daily lenses for a lengthy period, you may develop the following:
- Swelling and hazy eyesight
Extended-wear contacts are thinner and made of a more breathable substance, silicone hydrogel. This permits adequate oxygen to reach the eye. However, you should never wear your extended-wear contacts for more than the suggested time. If you do, you will be more likely to develop more severe symptoms, such as keratitis.