Assessing Distance Vision
Assessing distance vision requires understanding what a patient CAN see, what they WANT to see, and determining the right magnification level to meet their needs. This page contains our process and tools for finding the right low vision device for a particular patient's vision goals.
Tech Optics' Process for Addressing Distance Vision Challenges
What CAN Your Patient 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 Does Your Patient 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 tasks 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
To use the calculator below, first input the measured acuity (what the patient can see). Then input the goal acuity (what the patient wants to see). The result will indicate what magnification level is appropriate for the patient's goal.
Find the Right Device
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.