Narcissus can have a deleterious effect on image quality for cooled infrared imaging systems. Therefore, analysis of narcissus is important for designing both scanning and staring optics. Narcissus is generally assumed to be negligible in staring IR optical designs because the shading effects can be removed by calibration of the detector array data. However, the calibration usually decreases sensitiveness of the system and Narcissus variation may be noticeable for sensors when the conditions changes as follows: 1. warming and cooling the optical housing, 2. zooming optical elements, 3. movement of lenses for focus. In that case, it will result in shading and other image defects even after calibration. To minimize these effects, narcissus should be assessed and controlled during the design of staring array IR system. We provided a direct and fast method for analyzing the narcissus variation in the presence of software such as LightTools, TracePro and ASAP, and proposed the principles in optical design of staring IR systems to reduce narcissus. A cooled staring IR system with serious narcissus was estimated and reoptimized. Narcissus analysis of this IR system confirmed the efficiency of the analysis method.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.