Since I left you, mine eye is in my mind;
And that which governs me to go about
Doth part his function and is partly blind,
Seems seeing, but effectually is out;
For it no form delivers to the heart
Of bird, of flower, or shape which it doth latch:
Of his quick objects hath the mind no part,
Nor his own vision holds what it doth catch;
For if it see the rud'st or gentlest sight,
The most sweet favour or deformed'st creature,
The mountain or the sea, the day or night,
The crow, or dove, it shapes them to your feature.
Incapable of more, replete with you,
My most true mind thus maketh mine eye untrue.

William Shakespeare

http://www.poemhunter.com/poem/sonnet-113-since-i-left-you-mine-eye-is-in-my-mind/