The therapeutic value of a medication is called its efficacy.
<span>A stereoscope uses two pictures from slightly
different viewpoints in order to provide the illusion in 2-d images. The two slightly different pictures of the same object or scene
will be seen by the left eye and the other picture will be seen by the right
eye, and then when they are viewed in stereoscope, the two pictures were fused
perceptually into single image containing depth. </span>
