Your doctor may order a PAM test to determine your best visual acuity. This vision test reflects an eye chart directly onto the retina. If the patient notices a marked improvement in their vision, a retinal disorder is most likely not the cause for the decreased vision.  This simple, non-invasive test is important because it can help the doctor determine if a patient's decreased vision is due to a cataract, another form of media opacity, or is limited due to retinal disease.