Show The Advantage of Two Eyes In responce to the question What is the use of having two eyes the answer baa been given To have one left if the other la i hurt U Much as we may admire the sagacious foresight of this youthful physiologist physiolo-gist it will not be found sufficient to rest contented with his ultima a tum He had evidently not tried his skill to find how unexpectedly he would miss the inkstand while endeavoring en-deavoring to dip his pen into it at arms length with one eye closed He had not thought of holding bis finger a few inches i in front of his face > to find what part of the wall it would hide from each eye in succession suc-cession or how differently it wouk look when regarded from those two points of view separately how much thicker it would appear when both eyes were open how readily he could examine three sides of it at once how much more cefinitely he i could judge j its distance in a word how much more comprehensive was the information given by two eyes if used at the same moment Assuming As-suming that he knows exactly how to account for the inversion of the retinal image and the erect appear ance of the object there pictured how our visual perceptions are only signs of what we momentarily feel on the retina signs that generally represent the realities with a fair degree of accuracy but may sometimes some-times represent almost anything else on demand how if the eyes be healthy we have no consciousness conscious-ness of possessing any retina at all b t instantly and unconsciously refer re-fer every retinal sensation to some external body whose existence we are obliged to assume unless there be special arguments to convince us to the contrary granting all this our young physiologist has not thought of inquiring how it is that i although two retinal images are i produced we see but a single object ob-ject and this despite the fact that like photographs of the same body simultaneously taken from different standpoints these two images are necessarily dissimilar W Le Conic Stevens in Popular Science Monthly for May |