What is a sound way to determine if eyes are irritated from contact lenses?

If you feel eyes: Contact lenses cause a general decrease in oxygen to the cornea. They can also cause discomfort in the form of foreign body sensation especially when blinking, redness of white part of eye, irritation, chronic tearing, fluctuating blurry vision, pain. If you have any of these symptoms, your contacts may be irritating your eye. An eyemd can take a look under the microscope to check.