The circle lenses allow less oxygen to the eye, often contain less water, sometimes the color on them is irritating. Doctors have recommended things like not leaving them in longer than 3 hours at a time. When you google it you have to dig around to find out that fake circle lenses are also being sold and they are inferior products to the major brands. Another issue is proper fit. It would seem easy enough to get a contact prescription with your eye measurements though. They are not that different from other contacts but they are different. Most regular contacts are thinner, contain more water, breath better, can be worn longer.
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