With Halloween fast approaching, the FDA has this week released a consumer safety warning regarding costume contact lenses. The agency is reminding the public that while over-the-counter fashion lenses may enhance the holiday fun, they are dangerous and could potentially lead to serious vision-threatening problems.

According to federal regulators, contact lenses are medical devices that should not be purchased without a prescription, and choosing the wrong lenses could lead to serious eye damage. Moreover, even properly prescribed contact lenses place the wearer at risk for infection, so the buyers of ill-fitting fashion contact lenses are at an even greater risk for problems.

The FDA is urging consumers to buy fashion lenses only when prescribed by their optometrist or ophthalmologist. Purchasing decorative lenses from unreliable vendors is dangerous, as these products are of poor quality and can cause issues such as redness, eye pain and decreased vision. Moreover, the agency suggests that anyone experiencing unusual or painful side effects due to the use of contact lenses to visit their doctor immediately.