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.
In music, the subdominant is the technical name for the fourth tonal degree of the diatonic scale. It is so called because it is the same distance  below  the tonic as the dominant is above the tonic-in other words, the tonic is the dominant of the subdominant. It also happens to be the note immediately below the dominant. It is sung as fa in solfege.