An auxiliary optical system (600, 700) configured to be removably attachable to a mobile electronic communication device having a protruding onboard camera on a front face and a smooth, continuous protruding ring surrounding the onboard camera, the auxiliary optical system (600, 700) comprising: a retainer portion (606, 770) configured to be removably attachable to the mobile electronic communication device, the retainer portion (606, 770) comprising at least a front portion (607, 714) configured to contact the front face of the mobile electronic communication device, at least a second portion (609, 620, 719, 720) configured to contact another face or edge of the mobile electronic communication device, a seating region (617, 716) configured to correspond with a portion of a protruding surface of the on-board camera, and a channel (615, 710) formed as a recessed pathway on the front portion that is configured to receive the protruding ring; at least one optical component (402, 411) attached or attachable to the retainer portion (606, 770) such that the optical component (402, 411) is configured to be in optical communication with the onboard camera of the mobile electronic communication device when the retainer portion (606, 770) is attached to the mobile electronic communication device; wherein the retainer portion (606, 770) is configured to be moved into position on the mobile electronic communication device such that the protruding ring and the on-board camera slide within the channel (615, 710) until the on-board camera reaches the seating region (617, 716) and the retainer portion (606, 770) contacts the front face of the mobile electronic communication device in a region adjacent to the protruding ring in a secure manner that resists sliding. a retainer portion (606, 770) configured to be removably attachable to the mobile electronic communication device, the retainer portion (606, 770) comprising at least a front portion (607, 714) configured to contact the front face of the mobile electronic communication device, at least a second portion (609, 620, 719, 720) configured to contact another face or edge of the mobile electronic communication device, a seating region (617, 716) configured to correspond with a portion of a protruding surface of the on-board camera, and a channel (615, 710) formed as a recessed pathway on the front portion that is configured to receive the protruding ring; at least one optical component (402, 411) attached or attachable to the retainer portion (606, 770) such that the optical component (402, 411) is configured to be in optical communication with the onboard camera of the mobile electronic communication device when the retainer portion (606, 770) is attached to the mobile electronic communication device; wherein the retainer portion (606, 770) is configured to be moved into position on the mobile electronic communication device such that the protruding ring and the on-board camera slide within the channel (615, 710) until the on-board camera reaches the seating region (617, 716) and the retainer portion (606, 770) contacts the front face of the mobile electronic communication device in a region adjacent to the protruding ring in a secure manner that resists sliding.