In 2009, in response to long term concerns regarding inconsistencies in the painting's disposition of darkness and light, conservators at the Philadelphia Museum of Art undertook restoration of "The Gross Clinic" from July 2009 to July 2010, during which time the painting was not publicly visible. The restoration sought to revert changes that had been made by the Jefferson Medical College during the 1917 restoration. Definition of parts, including Eakins' self-portrayal, was restored, using as reference an ink wash copy of the painting made by the artist, as well as a photograph taken by the Metropolitan Museum of Art previous to the Medical College's changes in 1917.