Surround Propinquity and Tonic Accommodation

Authors

Nguyen, Tammy; Stark, Lawrence R.

Surround Propinquity and Tonic Accommodation

publication date

Abstract/Introduction

Purpose

Previous studies of dark focus have found evidence of a propinquity response, in which subjects accommodate to the perceived distance of their surroundings despite being in absolute darkness. Their distance perception in a lighted room allows a spatial representation to persist within the darkened room. This study sought to establish the significance and magnitude of the propinquity response in a large sample of young adults, and to determine whether the propinquity response can be predicted by a subject’s initial dark focus in an unknown dark room.

Methods

Dark focus was measured with a dynamic infrared optometer (Plusoptix PowerRef 3) in 30 young adult subjects, 26 of whom were naive to the testing room and its dimensions. Dark focus was then measured at varying dioptric wall distances of 0.25–4D. The subject viewed the lighted room before each measurement. For each individual, the dark focus was plotted as a function of dioptric wall distance. The slope of this function was used as a measure of the propinquity response.

Conclusion/Results

Results

The mean initial dark focus value was 1.05D (SD 1.04D) for the 26 naive subjects. The mean slope of the plot of dark focus as a function of dioptric wall distance was small (+0.097), yet highly statistically significant (P = .0002). The propinquity response function showed no statistically significant quadratic or cubic trends, and so may be considered linear. No statistically significant correlation was found between naive dark focus and propinquity response (r = +0.246, P = .226).

Conclusions

Propinquity seems to be a small but statistically significant factor in dark focus measurements. Though it is unlikely to contaminate tonic accommodation measurements in large samples under normal laboratory conditions, a minority of individuals exhibit large propinquity responses equal to that of proximal accommodation in lighted conditions.

Testimonials

At Amplify with Dr Wernick I was seeking help for seemingly intractable, probably age-related dryness. I've seen other doctors about it, and that has been helpful, but what he explained to me about it and the careful way he answered all my questions gave me so much more of a clear understanding of what is going on (and is not) that I am more able to implement all his and others' recommendations than I was before. And he gave me additional resources for further follow-up. I am most grateful.

Cynthia Norton

Wow! This is a great Eye Care medical facility. I was thoroughly examined by Dr. Pinkhasov for over 2 hours. She made sure to check my eyes for pretty much everything and patiently explained proper care for my eyes. They definitely know how to provide great care and treat their patients right. Now I know why they have such a great reputation and been around for so long.

Steve Fay

Dr. Kavner is a gifted diagnostician and orthoptic therapist. He treated me several decades ago for a condition similar to dyslexia. I was having migraines five times per week. I worked with him for about a year and I experienced tremendous improvement (down to 3-4 per year) that has lasted.

Mary K.

Dr. Kavner recommended two types of eye therapy for my daughter. One of them using bio-feedback. In just three sessions she is seeing considerably better. She shouted this morning: Ooh my God! I could not see these letters with my glasses on, and now I can see them without my glasses. If you are willing and able to invest in improving your vision, this is a good place to go to!

Peter G.

Dr. Kavner recommended two types of eye therapy for my daughter. One of them using bio-feedback. In just three sessions she is seeing considerably better. She shouted this morning: Ooh my God! I could not see these letters with my glasses on, and now I can see them without my glasses. If you are willing and able to invest in improving your vision, this is a good place to go to!

Kinkie F.

I have always found Dr Kavner's work, expertise and wisdom of the highest caliber. As one of the fathers of OT, occupational othomology, his depth and breadth of knowledge about the eyes' health and wellbeing of the patient is exemplary. Cannot say enough good things about him.