Can you wear 1-day contacts more then 1 day?

I've been a Certified Ophthalmic Medical Technician for 20 years. Daily and monthly disposable contacts are not a scam, but are not for everyone. Honestly, no, you should not wear 1 day disposables for multiple days. They're formulated and manufactured for 1 day wear. They aren't made to sit in cleaning solution overnight, and most people who wear 1 days, don't even have cleaning solutions. And bloodshot eyes are nothing from contacts, for the most part. The changes that come from overwearing your lenses, that could potentially harm your eyes, are those we see under the microscope on exam. When you notice a problem, it's too late in a lot of cases. Don't save the bucks, wear them 1 day and throw them. You'll be at risk of corneal ulcers, abrasions, and neovascularization (as well as other things) if you don't. There's a reason why the FDA has only approved them for 1 day use. Now, if you overwear them will you definitely have a problem? Hard to say. But we do multiple corneal transplants each year on people who misuse their contacts, and it's not like you can buy new corneas at Wal-Mart.

Daily contact lenses are meant to be worn for one day. The lens material is thinner, and more permeable to oxygen and water than standard lenses. The increased permeability to water means that it's easier for bacteria and fungi to set up housekeeping in the lens. Your eyes will probably become irritated and may become infected. It's just not a good idea.