Shakespeare's Sonnet 24

Mine eye hath play’d the painter and hath stell’d,Thy beauty’s form in table of my heart;My body is the frame wherein ’tis held,And perspective it is best painter’s art.For through the painter must you see his skill,To find where your true image pictur’d lies,Which in my bosom’s shop is hanging still,That hath his windows glazed with thine eyes.Now see what good turns eyes for eyes have done:Mine eyes have drawn thy shape, and thine for meAre windows to my breast, where-through the sunDelights to peep, to gaze therein on thee;Yet eyes this cunning want to grace their art,They draw but what they see, know not the heart.

My eyes have acted as a painter and fixed your beautiful likeness on the canvas of my heart. My body is the frame that holds it, and showing depth is the painter's finest skill.
You must look through the painter's eyes to appreciate his skill and find where your true image lies. It still hangs in the workshop of my chest, whose windows are glazed with your eyes.
Now see what favors our eyes have done for each other: mine have drawn your likeness, and yours are windows into my chest. Through them the sun delights to peek and gaze at you inside.
Yet eyes lack one skill that would perfect their art: they draw only what they see and cannot know the heart.