...Painted in Philadelphia, the work could be described as a double portrait because the geranium, reputed to be the first specimen of this exotic plant ever grown in the New World, is as lovingly portrayed as the painter's brother is is. The Peale family often collaborated in their endeavors, and here Rembrandt commemorated his brother's horticultural triumph. Rembrandt's own skill is evident in the clearly defined pools of light on Rubens' cheeks. In a phenomenon familiar to all, his glasses focus the beams passing through them, thereby forming the brighter disks of light under his eyes. Rubens Peale with a Geranium is a supreme example of the unaffected naturalism which... (http://www.nga.gov/content/ngaweb/Collection/art-object-page.66250.html) This set a record for an American work of art sold at auction. Art history and ophthalmology scholars have studied the painting, and have theories for this unusual depiction of eyeglasses. (https://en.wikipedia.org/wiki/Rubens_Peale)