I saw thee weep--the big bright tear
Came o'er that eye of blue;
And then methought it did appear
A violet dropping dew:
I saw thee smile--the sapphire's blaze
Beside thee ceased to shine;
It could not match the living rays
That filled that glance of thine.
As clouds from yonder sun receive
A deep and mellow dye,
Which scarce the shade of coming eve
Can banish from the sky,
Those smiles unto the moodiest mind
Their own pure joy impart;
Their sunshine leaves a glow behind
That lightens o'er the heart.

George Gordon Byron

http://www.poemhunter.com/poem/i-saw-thee-weep-2/