The CYA test should really be done in bright sunlight with your back to the sun and the tester at your waist in the shadow of your body. I like to pour the solution to each line, look away and look back. If I see the dot, I pour to the next line, and so forth until I come to the line that I don't see the dot when I look back. Try not to stare at the dot for too long. Your mind will play tricks on you. Look away, look back.