Skills lab- Vision

Question 1

What do you need to know about giving an eye exam? (lighting and patient behavior)

Answer 1

Conduct in well lit room and Watch for squinting, leaning, closing one eye when testing both eyes, excessive blinking, and/or watering of the eyes

Question 2

Snellen charts

Answer 2

Most common type contains letters
Patient reads letters of various sizes
Important to make sure patient knows all the letters of the alphabet
Characters (E, letters, pictures) have specific heights
Range from small on bottom to largest on the top
Normal vision – see 20mm high figures while standing at a distance of 20 feet
Top number represents the distance the patient is standing from the chart.
Some charts vary in distance – letters are calibrated accordingly
Lower bottom number refers to the height of the characters the patient can read
Snellen charts test for defects in distant vision, nearsightedness, myopia
Not specific diseases

Question 3

Ishihara Method

Answer 3

Ishihara Method most common
Series of numbers printed in colored dots against a black background of dots on contrasting colors
Patients with normal color vision can readily identify the number
Patients with color blindness will not be able to identify the number
Most accurate test in natural light