LENS training is not known by most doctors because it is not approved by the FDA for diagnosing or treating any disease or injury. It has been around since 2006. It has an "exemption" status with the FDA. It can only be promoted as a relaxation device.

There are other true neuro-feedback systems (volitional neuro-feedback requires the patient to act to make the brain behave a desired way). LENS is a non-volitional neuro-therapy system. The patient does nothing but sit while the LENS device does its thing.

This subject has been discussed extensively in prior threads.