Week of 01/09/17 Visual Acuity

Objectives:
The student will be able to:

• Describe the importance of vision screening and early identification
• Determine distance for a variety of visual acuity testing needs
• Determine proper lighting and placement (sitting, standing) to achieve the optimum contrast sensitivity
• Document vision screening results

Visual acuity measurement is a good screening tool because normal visual acuity requires that all levels of the visual system function properly.  The optical system of the eye must project a sharp image of the outside world onto the retina.  The retina must then be able to translate this image into neural impulses. Finally, the neural impulses must travel to the brain, where they are analyzed and recognized.  Therefore, a wide array of different visual disorders (but not all) can affect visual acuity.

Because visual acuity is so easily measured, it is often used as a primary eligibility criterion, such as 20/20 for a pilot’s license, 20/40 for a driver’s license, 20/200 for certain disability benefits.

STUDY RESOURCES:

Snellen Chart

What does "20/20 Vision" mean? Optimal Vision With your Spectacles Glasses Video

ACTIVITY:
1. Visual Acuity Testing

TEST: Written and Practical - TBA