As this eminent Part hath not been pretermitted by Authors, that have made it their particular Design and Business to speak of the Works of God; so divers of the aforesaid Particulars have been touched upon by them. And therefore I shall take in as little as possible of what they have said, and as near as I can, mention chiefly what they have omitted. And,
1. For the Form of the Eye; which is for the most part Globous, or somewhat of the sphæroidal Form: Which is far the most commodious optical Form, as being fittest to contain the Humours within, and to receive the Images of Objects from without[]. Was it a Cube, or of any multangular Form, some of its Parts would lie too far off[c], and some too nigh those lenticular Humours, which by their Refractions cause Vision. But by Means of the Form before-mentioned, the Humours of the Eye are commodiously laid together, to perform their Office of Refraction; and the Retina, and every other Part of that little darkned Cell, is neatly adapted regularly to receive the Images from without, and to convey them accordingly to the common Sensory in the Brain.
To this we may add the aptitude of this Figure to the Motion of the Eye, for it is necessary for the Eye to move this way, and that way, in order to adjust it self to the Objects it would view; so by this Figure it is well prepared for such Motions, so that it can with great Facility and Dexterity direct it self as occasion requires.
And as the Figure, so no less commodious is,
2. The Situation of the Eye, namely in the Head[d], the most erect, eminent Part of the Body, near the most sensible, vital Part, the Brain. By its Eminence in the Body, it is prepar’d to take in the more[e] Objects. And by its Situation in the Head, besides its Proximity to the Brain, it is in the most convenient Place for Defence and Security. In the Hands, it might indeed (in Man) be render’d more eminent than the Head, and be turned about here and there at pleasure. But then it would be exposed to many Injuries in that active Part, and the Hands[f] render’d a less active and useful Part. And the like may be said to its Sight, in any other Part of the Body, but where it is. But in the Head, both of Man, and other Animals, it is placed in a Part that seems to be contrived, and made chiefly for the Action of the principal Senses.
Another Thing observable in the Sight of the Eye, is the Manner of its Situation in the Head, in the Fore-part, or Side-part thereof; according to the particular Occasions of particular Animals. In Man, and some other Creatures, it is placed to look directly forward chiefly; but withal it is so order’d, as to take in near the Hemisphere before it. In Birds, and some other Creatures, the Eyes are so seated, as to take in near a whole Sphere, that they may the better seek their Food, and escape Dangers. And in some Creatures they are seated, so as to see best behind them[g], or on each Side, whereby they are enabled to see their Enemy that pursues them that way, and so make their Escape.
And for the Assistance of the Eyes, and some of the other Senses in their Actions; the Head is generally made to turn here and there, and move as Occasion requires. Which leads me to the
3. Thing to be remarked upon, the Motions of the Eye it self. And this is generally upwards, downwards, backwards, forwards, and every way[h], for the better, more easy, and distinct Reception of the visual Rays.