Cone of light Cone of light The cone of light, or light reflex, is a visible phenomenon which occurs upon examination of the tympanic membrane with an otoscope. Shining light on the tympanic membrane causes a cone-shaped reflection of light to appear in the anterior inferior quadrant. This corresponds to the 4 o'clock to 5 o'clock position in the right eardrum and the 7 o'clock to 8 o'clock position in the left eardrum. The apex of the cone is at the most depressed part of the tympanic membrane, known as the umbo. The absence of a cone of light does not necessarily signify
Common name or coinages; such names generally are difficult for laymen to learn, remember, and pronounce and so, in such books as field guides, biologists commonly publish lists of coined common names. Many examples of such common names simply are attempts to translate the Latinised name into English or some other vernacular. Such translation may be confusing in itself, or confusingly inaccurate, for example, "gratiosus" does not mean "gracile" and "gracilis" does not mean "graceful". The practice of coining common names has long been discouraged; de Candolle's "Laws of Botanical Nomenclature", 1868, the non-binding recommendations that form the basis of the modern