American Family Vision Clinic Logo
Authors
Schmid, Katrina L. PhD; Beavis, Stephanie D. MOptom; Wallace, Sophia I. MOptom; Chen, Joy MOptom; Chien, Yi-Tang MOptom; Nguyen, Terry MOptom; Tran, Amy MOptom; Varnas, Saulius R. PhD; Atchison, David A. DSc, PhD, FAAO

The Effect of Vertically Yoked Prisms on Binocular Vision and Accommodation

publication date
February 28, 2019
see more

Abstract/Introduction

SIGNIFICANCE 

Vertically yoked prisms have been used in treatment of binocular vision dysfunction despite minimal supporting evidence. In people with normal binocular vision, the impact on phorias has been assessed but not the impact on accommodation, accommodation vergence interactions, or the horopter. We found that vertically yoked prisms have minor effects during short-term wear in young adults.

PURPOSE 

The purpose of this study was to determine effects of vertically yoked prisms on accommodative response and several binocular vision tasks.

METHODS 

There were 45 participants aged 18 to 24 years. The 23 myopes wore distance-corrected soft contact lenses. In a random arrangement, each person wore spectacles containing planopower lenses with either 8 Δ base-up, 4 Δ base-up, zero, 4 Δ base-down, and 8 Δ base-down prisms. Before spectacle wear, baseline measurements of near heterophoria, accommodation response, negative and positive relative accommodations, fusional vergence, and Nonius-horopter spatial perception were taken. Measurements were repeated after a 40-minute wear, spectacles were removed, and tests were performed 20 minutes later. On a 22-participant subset, on a separate occasion, measurements of heterophoria, accommodation response, and relative accommodation were made immediately after spectacles were fitted.


Conclusion/Results

RESULTS 

Most changes relative to baseline were not significant. Where effects occurred, these were nearly all associated with prism presence rather than adaptation. There were significant effects on accommodation response, but these seem to be refraction effects produced by pantoscopic tilt–induced power changes rather than perceptual effects altering accommodation. There were statistically significant effects on negative relative accommodation (P < .01), with zero prism giving more negative relative accommodation than 8 Δ base-down prisms. Tendencies were noted for prisms to move horopter limits toward the observer. Effects were small and likely not of clinical relevance.

CONCLUSIONS 

Vertically yoked prisms have minor effects on accommodation and binocular vision, at least during short-term wear in young adults with normal binocular vision.


Testimonials


Such a nice optician. My grandson is only 4 and needs glasses. We were so sad, but he explained the issues, and we will follow up as he suggested.


Anna P.

I had such a good experience with the clinic. Very friendly staff and doctor, did not have to wait for long to be called, and was treated respectfully. Thanks, American Family.


June S.

Dr. Zurcher has gone above and beyond what any other eye doctor has ever done to figure out what is going on with my eyes. Very happy with American Family Vision.


Christine R.

Family Vision Clinic changed our lives! My daughter was frequently car sick, and she was getting headaches every day, often painful enough that they brought her to tears. We saw a string of doctors and therapists, but we made no progress. Finally, we found Dr. Levi Zurcher and his eye therapist Rain. After ten weeks of eye therapy my daughter no longer gets headaches, and she no longer gets car sick. Daily tears are a thing of the past. I really can’t say enough about this clinic. It was fascinating to watch Dr. Zurcher work. For the first time, someone who knew what they were doing was intently studying my daughter, really trying to figure out all of her eye issues, and his therapist Rain is one of the most patient and lovely people that I’ve ever had the good fortune to meet. We’re finished with eye therapy—yay!—and I have switched to American Family Vision Clinic for all of my family’s other eye health needs.


Lars Wulff

Very professional, yet kind and helpful. They do what they can to make the appointment comfortable. I was running a bit late, I made sure ti call. They were able to switch me with a patient who was already there, they treated me with respect, and helped my son have confidence by getting him the eye care he needed that day. Thank you so much! Would recommend to anyone. It's a blessing that they care enough to work with people who have all different types of insurance from work to state coverage.


Justin E.

The staff is friendly. The Doc is very knowledgeable. The office is family friendly and everyone is so patient with the little ones.


Amy Fagerness
1 2 3

Blog

close-up-of-an-adult-man-checking-eye-redness-in-f-HQYT3EJ

What Causes Bloodshot Eyes? Understanding the Causes and Treatments

Bloodshot eyes can be alarming, but they are not always a cause for concern. In this blog, we will discuss […]

Read More
child-46XPLXC

Ocular Rosacea: Understanding the Symptoms and Best Treatment Options

Rosacea is a skin condition that affects many people. While it is commonly found on the face, rosacea can also […]

Read More
adrian-swancar-roCfgvkBLVY-unsplash

Can Vision Therapy and Neuro Optometry Help with Motion Sickness?

Motion sickness can be debilitating and affect people's daily activities. Symptoms such as dizziness, nausea, car sickness, and balance problems […]

Read More
see all blogs

Contact Us To Amplify Your EyeCare

Working Hours

Monday - Thursday
8:00 am - 5:15pm
friday-sunday
Closed
Location
400 Yauger Way SW. Bldg 1, Ste A Olympia, WA 98502
Website Accessibility Policy
Safety protocols page
phone-handsetarrow-uparrow-right linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram