Since I left you, mine eye is in my minde,
And that which governes me to goe about,
Doth part his function, and is partly blind,
Seemes seeing, but effectually is out:
For it no forme delivers to the heart
Of bird, of flowre, or shape which it doth lack,
Of his quick objects hath the minde no part,
Nor his owne vision houlds what it doth catch:
For if it see the rud'st or gentlest sight,
The most sweet-favor or deformedst creature,
The mountaine, or the sea, the day, or night:
The Croe, the Dove, it shapes them to your feature.
Incapable of more, repleat with you,
My most true minde thus maketh mine untrue.
Changes to the original text
In the first quatrain, the poet observes that since he left his beloved, his eye is mainly in his minde, ie that he is rather paying attention to what is going on in his head than what is all around him.
In the second quatrain, the poet pursues this idea, commenting that he does not really see the things around him like birds or flowers, or, if he does, his mind does not hold on to them.
In the third quatrain, the poet relates that if his eye does see anything, whatever it is, it changes what it sees into his beloved.
In the final couplet, the poet states that, being full of his beloved, his mind, which is most true to his beloved, gives an untrue representation of the world.