There are few reasons why you may not see anything. First, make sure your sample is totally dried before looking into the lens. You will also want to be in bright light, either a sunny window or bright lamp. Hold the lens in front of your eye and move it toward or away from your eye until you see something. Even if you do not see ferning, you should see something. If there is absolutely nothing there, clean Ovatel and trying again. Make sure your sample does not cover the entire lens.