Assessing Distance Vision - Two Things to Know
What Can They See?
Using the Tech Optics Printable Distance Chart, you can assess a patient's distance visual acuity. The chart is calibrated for a distance of five(5) feet. Place the chart on a well-lit wall and stand 60 inches away. With their glasses on, the lowest line on which the patient can read 3 out of the 5 letters is the patient's distance visual acuity.
What Do They Want to See?
Determining goal acuity for distance can be a bit of a challenge. A patient's description of their challenges might not translate to an eye chart. They might say something like "I have trouble seeing faces." Here's a list of some common challenges, and their target acuities.
|Seeing Street Signs||20/30 - 20/40|
|Reading Captions on TV||20/20 - 20/50|
|Seeing Detail of Faces||20/20|
|Improved Recognition of People||20/100|
Calculating Distance Magnification
Find Devices That Will Help
In magnification, more is not better. You're making a trade. When you increase magnification, you reduce field of view. You want the minimum amount of magnification required to achieve the patient's goals so you can maximize their field of view.