At the time of this painting Gerard would have been around his mid-twenties, with most of his career achievements still ahead of him (this certainly matches up with his youthful features in this painting). It was his loss of sight from congenital syphilis that forced him to pursue theorism, having initially succeeded as a painter and etcher.
The disease is clearly evident in this painting, no attempt is made to disguise the health problems already been experienced by Gerard. The pleasing element to this is that despite his poor health, this creative man was able to somehow live on for many years to come, only passing away as late as 1711.
The painting itself picks up swollen elements to the face that fits with the disease he was experiencing. Despite never hiding away from the facial issues of his subject, Rembrandt van Rijn still managed to achieve a certain level of sympathy within his depiction.
This important artwork can now be found in the Metropolitan Museum of Art, having been gifted to them by Robert Lehman. This high profile art institution holds one of the finest art collections in the world and is amongst the most visited of all the world's galleries. It is impossible to list all of their artists here, but some of the highlights include paintings by Paul Klee, René Magritte (The Empire of Light), Pablo Picasso (Les Demoiselles d'Avignon), Claude Monet (Water Lilies triptych) and Salvador Dalí (The Persistence of Memory).