PureVision, released in 1999, was the first contact lens made of silicone hydrogel. The advantage of silicone hydrogel is its high oxygen permeability. This keeps the eyes healthy and comfortable throughout the day, and you can even wear the lenses when you are sleeping. They be worn safely 24 hours a day for up to 30 days of continuous wear, but always follow the prescriptions and recommendations of your optician. PureVision contact lenses provide rich contrasts and superior details.
PureVision contacts have an optical design that reduces so-called spherical aberrations, which results in optimal visual quality. Spherical aberration is a refractive error than can give blurred vision under lower lighting conditions, for example when you are driving in the dark.
The lens has received approval from the FDA for therapeutic use as bandage when treating some eye disorders or diseases.
A downside with silicone hydrogel is that lipid deposits can be built up on the lenses, which can give blurred vision and make the lenses uncomfortable. To avoid this, clean the lenses in the right type of solution and replace them frequently.