OFFISS (Optical Fiber Free Intravitreal Surgery System) was developed by Horiguchi et al. and presented in 2002. The authors used a wide angle microscope combined with a newly designed aspheric 40-diopter lens and a prismatic inverting optical system. When the surgeon needs to perform bimanual surgery, the 40-diopter lens can be swung into place between the microscope and the patient’s eye. The illumination of the microscope gives an inverted image of the fundus which may be returned to an upright position with the use of an inverting optical system. A commercial version of OFFISS became available in 2003 ; produced by Topcon Company, Tokyo, Japan.