Red, itchy or irritated eyes are all symptoms of contact lens misuse.

Proteins in tears can build up on the contact lens, resulting in a lack of oxygen to the eye.

“Sometimes your body can recognize the proteins as foreign, so you can have reactions,” said Robin Apfelbeck, a Waterloo optometrist.

She recommends daily use contacts over monthly ones, as they do not require cleaning and are less susceptible to buildup.

Daily contacts can also pose problems, however. These can arise when they are fit poorly or left in too long.

“Everybody’s eyes are different, so you have to fit them properly,” Apfelbeck said.

Apfelbeck also suggested yearly eye exams to increase her patients’ overall eye health.