Definition of Acuity test, visual

Acuity test, visual: This test measures how well you see
at various distances. It is the familiar eye chart test.
The eye chart itself -- the usual one is called Snellen's chart
-- is imprinted with block letters that line-by-line decrease in
size, corresponding to the distance at which that line of letters is
normally visible.
The letters on Snellen's chart are, not surprisingly, called
Snellen's test type. Each block letter is quite scientific in design
(so that at the appropriate distance the letter subtends a visual
angle of 5 degrees and each component part subtends an angle of 1
minute).
The chart and the letters are named for a 19th-century Dutch
ophthalmologist Hermann Snellen (1834-1908) who came up with them as
a test of visual acuity. Visual acuity refers to the clarity or
clearness of the vision, a measure of how well a person sees. The
word "acuity" comes from the Latin "acuitas" = sharpness.

Definition of Acou-

Acou-: Combining form relating to hearing. As
in acoustic, otoacoustic emission test, and presbyacousia.

Definition of ABR test

ABR test: Auditory brainstem response test. A test for hearing and brain (neurological) functioning. ABR may be used in the evaluation of:

Hearing integrity (and neurologic normalcy) in infants and young children.
Neurologic integrity (and hearing) in patients who are comatose, unresponsive, or impaired due to a stroke, an acoustic neuroma (tumor on the hearing nerve), Meniere's disease, etc.


The ABR test involves attaching electrodes to the head to record electrical activity from the auditory nerve (the hearing nerve) and other parts of the brain. Also known as brainstem auditory evoked potentials (BAEP).