The American Optometric Association (AOA) has written to Facebook founder Mark Zuckerberg, asking the social media giant not to accept advertising from online eye test developer, Opternative.

Fighting fire from the health industry, Opternative, which is finalising partnerships to enter New Zealand and Australia, is also the subject of enforcement action by the US Food and Drug Administration (FDA) for what the FDA said is a lack of review of the product’s safety and efficacy and premarket approval prior to marketing.

“Given the serious nature of the FDA warning against Opternative, we wanted to ensure that you are aware that your platform is being used to advertise a company that has marketed its app-based vision test without clearance or approval required by the government, in violation of federal law,” AOA recent past president Christopher Quinn told Zuckerberg.

Opternative claims its digital refractive test can be used by its partners to offer vision tests and acuity screenings, anywhere at any time and said it is working with the FDA to comply with regulatory requirements.

The Facebook letter is the latest weapon employed by the AOA against Opternative, which has previously raised questions about the Opternative product’s safety and efficacy and concerns about inaccurate prescriptions and the inability of the product to diagnose more serious health conditions.