Are Soft Lenses More Comfortable than Rigid Gas Permeable Lenses?
Soft contact lenses are worn by most people who prefer lenses over glasses, but gas permeable lenses can be a more comfortable option for some wearers. Here’s why.
Millions of people wear contact lenses, with around 80% choosing a soft lens as prescribed by their optician. Advances in technology in recent years mean that soft lenses are now available as daily, weekly and monthly disposables requiring a minimum of cleaning, rubbing and disinfecting.
Disposable contact lenses, made from ultra-thin plastic, are immediately comfortable to wear and are cost-effective as most do not require anything more than a single multi-purpose contact lens solution for disinfecting and storing lenses when not in use.
The technology behind rigid gas permeable lenses or RGPs is actually newer than traditional soft lenses and was invented to replace the old-fashioned “hard” lenses made of a substance called PMMA (polymethyl methacrylate). RGP’s are made of plastic containing silicone, which, unlike PMMA, allows oxygen to pass through the lens, offering greater comfort for some wearers than traditional soft contact lenses made from plastic containing water called polymer hydrogels.
RGP Contact Lenses
Gas permeable contact lenses have a smaller diameter than soft lenses and sit within the iris rather than extending beyond it. Many users find them easier to use as, being rigid, they cannot be inserted inside out or torn with a fingernail. Whilst removing them takes a little practice, as the lens needs to be “flicked” out by pulling the eye upwards rather than “pinching” out the lens, this is also preferred by some wearers who hate the thought of touching the eyeball with their fingers.
Other advantages include greater clarity of vision and cost-effective longevity as with careful use, they can last for 2 to 3 years, provided the patient’s prescription does not change. Add to that the comfort advantages of wearing a lens that covers less of the eye, thereby allowing eyes to breathe more easily and the question has to be asked why more patients do not wear RGP lenses?
Why Wear Disposable Contact Lenses over Gas Permeable Lenses?
There are several reasons why wearers prefer soft disposable contacts:
- Users have to build up to wearing RGP lenses gradually, starting with 2 hours per day and adding an hour or so per day until the maximum wear time of around 12 to 14 hours is reached.
- RGP lenses cannot be easily alternated with eyeglasses as they need to be worn every day for maximum comfort; users who leave them out for a week have to get used to them all over again.
- As they are reusable rather than disposable, they need greater care including weekly disinfection with protein removing tablets, which is time-consuming and means lenses cannot be worn again for several hours after disinfection.
This last reason is probably the main one behind the dramatic growth in daily disposable soft lenses; wearers simply insert a new lens every day and only need to buy small bottles of contact lens solution for occasional wetting or cleaning of lenses during the day.
New Silicone Hydrogel Soft Contact Lenses
The latest generation of disposable lenses containing the silicone used in RPG’s now offers even greater comfort for wearers. Hydrogels alone can only let a certain amount of oxygen through to the eye via the water-based portion of the lens, whereas the addition of silicone allows up to seven times more oxygen through, and the moisture cushion makes them leading disposable contacts. Daily users will almost certainly find these new lenses more comfortable and the technology has introduced a much safer extended wear lens of up to 30 days, previously considered unhealthy due to the high risks of eye infection.
Most Comfortable Contact Lenses
Whilst it is harder to get used to wearing RGP lenses, some wearers find them more comfortable to wear and use and, with clearer vision and durability, a better option than more expensive disposable lenses. The latest advances in silicone hydrogel soft lens technology, however, offer far more comfortable disposable lenses, which can be alternated with eyeglasses and require minimal contact lens care.