Contact Lens Eye Diseases

Posted On: January 31, 2021


By Ross Pelton, RPh, PhD, CCN
Scientific Director, Essential Formulas

The purpose of this article is to make people aware of the microbiome in the eyes and to publicize the fact that wearing contact lenses increases the risk of creating “ocular dysbiosis” and the development of eye diseases.

The Human Microbiome Project (HMP) was launched in 2008 with an initial goal of characterizing the microbiome from the following five different body sites: skin, urinary tract, nasal mucosa, oral cavity, and the gastrointestinal tract.

When the HMP was launched, the bacteria in the eye, known as the “ocular microbiome,” was omitted, mainly because far fewer bacteria are present in the eyes. However, newer genetic sequencing technologies are rapidly increasing scientific interest in the ocular microbiome.

Ocular Dysbiosis: Wearing contact lenses changes the microbiome in the eyes. Studies have shown that the ocular microbiome of contact lens wearers is more similar to the microbiome found on the skin than the microbiome found in the eyes of people who do not wear contact lenses.i

Changes in the ocular microbiome from wearing contact lenses increases the risk of developing contact lens-related eye infections. It is estimated that 80% to 90% of eye infections are bacterial.ii One of the leading causes of these eye infections is bad contact lens cleaning habits and procedures.iii Studies report that up to 50% of contact lens wearers are not compliant with proper handwashing procedures.iv

Another reason that eye problems develop more frequently in the eyes of contact lens wearers is that contact lenses cause lens-induced hypoxia. Less oxygen encourages the proliferation of less beneficial bacteria and can result in eye-redness, inflammation, and various eye diseases.v

How to reduce the risk of eye infections from contact lenses

Experts make the following recommendations to reduce risks of eye infections from contacts:

  1. Keep your lenses and lens case clean.
  2. Wash your hands well before you handle your contacts.
  3. Take out your lenses, even extended-wear ones, before you go to sleep.
  4. Don’t wear your contacts in the shower, bath, or hot tub.
  5. Don’t reuse or “top off” cleaning solution.

People are strongly advised to make an appointment to be evaluated by an ophthalmologist or an optometrist.


i Shin H, et al. Changes in the Eye Microbiota Associated with Contact Lens Wearing. mBio. 2016 Mar-Apr’7(2):e00198-16.
ii Eye Care from Health Essentials/Cleveland Clinic. Avoid These Eye Infections from Bab Contact Lens Habits. Dec. 24, 2020.
iii Wu YT, et al. The effect of contact lens hygiene behavior on lens case contamination.
iv Fonn D and Jones L. Hand hygiene are linked to microbial keratitis and corneal inflammatory events. Contact Lens and Anterior Eye. April 2019;42(2):132-135.
v Efron N. Contact lens wear is intrinsically inflammatory. Clin Exp Optom. 2017 Jan;100(1):3-19.