(NEXSTAR) — The Food and Drug Administration (FDA) is warning consumers not to use two brands of eye drops due to contamination that could cause a potentially deadly infection.

Tests of the drops, Dr. Berne’s MSM Drops 5% Solution and LightEyez MSM Eye Drops – Eye repair, found bacterial and fungal contamination, the FDA said in a news release Tuesday. Using the products could result in a “serious vision-threatening infection which could possibly progress to a life-threatening infection,” according to the FDA.

To sell eye drops in the U.S., the product must be sterile to be safe for use, the Food, Drug and Cosmetic Act states.

Both products were being illegally marketed and would never have been deemed safe, according to the FDA, because they contain methylsulfonylmethane (MSM) as an active ingredient.

“There are no legally marketed opthalmic drugs that contain MSM as an active ingredient,” the release says.

While Dr. Berne’s gave the FDA a verbal agreement to voluntarily recall the drops, federal investigators say distributor LightEyez Limited has not responded to the FDA’s attempts to contact them.

The FDA says it is unaware of reports of health problems tied to the drops, but encourages anyone who experiences symptoms of an eye infection to seek medical care immediately.

If you already purchased the eye drops, the FDA recommends dropping them at a drug take-back site. If you cannot do that, there are other options listed on the FDA website.

The FDA is asking health care professionals and consumers to report any health or quality problems related to a medicine via the FDA’s MedWatch Adverse Event Reporting program.