Soft Contact Lenses versus Gas Permeable Lenses

There are two main classes of contact lenses in terms of the materials used, and these are soft and gas permeable lenses. Each of these has their own distinct advantages and disadvantages, and each can be obtained easily from an opticians. To find out what exactly the difference is between the two and which one might better suit you, read on.

Gas Permeable Lenses

Gas Permeable (GP lenses) are hard and rigid as they are made out of a plastic that allows oxygen (a gas) through the lens and to the eye beneath. Unlike hard lenses which were used before 1971, GP lenses, while rigid, allow the eye access to the oxygen it needs to remain healthy and happy. Silicon is an important component of these lenses as it allows for both rigidity and permeability.

GP lenses are great for anyone who is looking for the best possible quality of vision they can get out of their lenses, and for anyone with astigmatism as most other contacts don’t provide the same clarity. GP lenses can be made into bifocal, trifocal, and varifocal lenses unlike their softer counterparts, making them the condition of choice for anyone suffering from presbyopia.

Soft lenses

Unlike rigid GP lenses, soft lenses are made of a comfortable gel like material that fits just under the eye lid, allowing for instant ease and comfort. A relatively new form of soft lenses called silicon hydrogel lenses are composed of a very permeable material that supplies the eye with oxygen like a GP lens does, but without the initial discomfort .

Pros and cons of soft and gas permeable lenses

GP lenses have the advantage of providing more oxygen to the eye than traditional soft lenses (with the exception of silicon hydrogel lenses), as well as being more resistant to deposits of protein that accumulate on a soft lens which cause cloudy vision. GP lenses are also more robust because of their rigidity, and because of their durability they tend to last longer and hence be less expensive.

On the flip side however, soft lenses are instantly comfortable because of how malleable they are. GP lenses take a while to get comfortable in, and more importantly, you need to keep wearing them to maintain your level of comfort. If you choose to take GP lenses out for a week or more, you will find yourself needing another adjustment period. Soft lenses are also bigger and so less likely to become dislodged from the eye than GP lenses. Similarly this small size also contributes to the fact that GP lenses are designed to move as you blink, meaning there is a likelihood of unwanted debris getting underneath it and irritating your eyes.

Hybrid soft and GP contacts

Considering the fact that both soft and GP lenses have their own advantages, why not combine the two? That was exactly what SynergEyes were thinking when they came up with a hybrid lens composed of a GP centre and a soft outer part. This lens gives the clarity of vision GP’s are sought for while also making the lens a bit larger (and hence more safe) and more comfortable.

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