Abstract: Embodiments of the present disclosure provides an illumination device (300), comprises of one or more sources (301) which provides light arranged in a predefined configuration and a collar (303) with a first end (304) and a second end (305) to guide light received at the first end towards the second end. The collar guides the light in a medium between an internal wall and an external wall of the collar by reflection. The light from the second end is used to illuminate a target area for an imaging device. The method of illuminating a target area by an illumination device comprises of powering one or more sources to provide light for illumination and guiding the light in the medium to illuminate on the target area.