A paronychia is an infection of the skin that surrounds a toenail or fingernail. Acute paronychia â This usually appears as a sudden, very painful area of swelling, warmth and redness around a fingernail or toenail, usually after an injury to the area.
Definition of 'reflector'. reflector (rÉªflektÉÊ³ ) A reflector is a small piece of specially patterned glass or plastic which is fitted to the back of a bicycle or car or to a post beside the road, and which glows when light shines on it. A reflector is a type of telescope which uses a mirror that is shaped like a ball.
The main problem involving reflector telescopes is the spherical aberration, which is caused by the focal length not being the same for wider parts of the mirror. This can be corrected by using parabolic mirrors instead of spherical mirrors. What is the difference between refractor and reflector telescopes?