6 In proportion, therefore, as you find fault with the meanness of the substance, be so much the more astonished at the greatness of the art displayed. For this reason also, I do not so much admire the statuary who forms a beautiful figure out of gold, as him who, by the resources of art, is able, even in crumbling clay, to exhibit a marvellous and inimitable mould of beauty. In the former case, the material gives some aid to the artist, but in the latter, there is a naked display of his art.
Would you learn then, how great the wisdom of the Creator is, consider what it is that is made out of clay? What else is there but brick and tile? Nevertheless, God, the Supreme Artist, from the same material of which only the brick and tile is formed, has been able to make an eye so beautiful, as to astonish all who behold it, and to implant in it such power, that it can at once survey the high aerial expanse, and by the aid of a small pupil embrace the mountains, forests, hills, the ocean, yea, the heaven, by so small a thing!
Tell me not then of tears and rheums, for these things are the fruit of your sin; but consider its beauty, and visual power; and how it is that while it ranges over such an expanse of air, it experiences no weariness or distress! The feet indeed become tired and weakened even after going but a small distance; but the eye, in traversing a space so lofty and so wide, is not sensible of any infirmity. For since this is the most necessary to us of all our members, He has not suffered it to be oppressed with fatigue; in order that the service it renders us might be free and unfettered.
Source: Homilies on the Statues (New Advent)