Age-related macular degeneration (AMD or ARMD) is the most common cause of vision loss in those aged over 50. It causes a gradual loss of central (but not peripheral) vision. Central vision is needed for detailed work and for things like reading and driving. The disease does not lead to complete blindness.
Definition of Dissonance Dissonance is the use of impolite, harsh-sounding, and unusual words in poetry. In other words, it is a deliberate use of inharmonious words, phrases, or syllables intended to create harsh sounding effects.
Festinger's definition of cognitive-dissonance is the perception, by a subject, of a difference, of variable intensity, between what has been previously perceived and learned and new information. This process is illustrated by Figure 2.