Once we get over 50, optometrists perform routine tests for glaucoma. Two of the most common are the Visual field test that evaluates side vision and Tonometry, measures the pressure inside your eye after numbing your eyes with drops. It’s usually the initial screening test for glaucoma.
The Visual Field Test checks your peripheral vision, to see whether your visual field has been affected by glaucoma. In this test, you focus on a yellow dot while pressing a clicker when you see small white lights flash in various parts of the screen.
There are several things that make this test difficult when you have NLD:
- Focusing on the light requires lots of concentration
- Fine motor / coordination issues interfere with pressing the clicker
- Visual-spatial weaknesses
- Delayed response time (our brains often work slower, especially in areas that require visual motor integration, as this task does).
I have had this test. And yes it is difficult for folks with NLD for all the above reasons. However, since the Tonometry test found that my intraocular pressure was fine, and the visual field test was the same as when I took it two years prior, my optometrist concluded that I did not have glaucoma. It’s when both the pressure and the peripheral vision test are bad that you really have to worry.
The thing is, I’ve had poor peripheral vision all my life. It’s just that no one bothered to test it, since at a younger age I wasn’t at a risk for glaucoma.
Understanding that I have neurological issues and my peripheral vision has always been impaired helped the doctors, though they did send me to a specialist to rule out glaucoma. This was a few years ago.
One of the positive things of this test was that my optometrist, Dr. Miller, was the FIRST one EVER to explain to me that my peripheral vision is WORST looking DOWN. I finally understood why it is that I have always had problems knocking over ‘wet floor’ signs in stores and running into toddlers! And why when I was in college, someone thought I was depressed because I always looked down and the ground when walking! (Hint: I need to look down in order to see where i’m going!)
It may also be why, though I’ve had bifocals for years now, I’m still not used to them… I cannot wear them when walking in the woods, because I have to look at my feet and the bottom part interferes. Walking in stores / sidewalks /hallways is OK because you’re not likely to trip over stuff, but still, I’m always taking them off… I think in the future I will ask for just 2 pairs of glasses instead, a distance pair and a reading pair.