Holding a vision screening instrument and wearing contact lenses, like this one in the movie, can you tell?

An experienced doctor can tell at a glance whether you are wearing contact lenses, which is still a bit obvious. General eye examination is carried out under slit lamp, which can be detected. But the vision screening instrument is operated by itself, not under the guidance of professionals. Wear contact lenses, the instrument should not see. After all, the final degree will be biased through contact lenses. Vision screening is the most important means for early children to find amblyopia. This instrument has the advantages of objectivity, accuracy and rapidity, but it doesn't take a long time to do such a test. This machine is made by using the optical principle to measure the diopter of the lens. The child's retina is not fully developed, and it has little effect if it is not detected frequently.