June 2017
Volume 58, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2017
Defocus vibrations improve visual resolution of defocused targets
Author Affiliations & Notes
  • Maciej Marcin Bartuzel
    Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
    Vision Science Research Group (CiViUM), University of Murcia, Murcia, Spain
  • Ivan Marin-Franch
    Vision Science Research Group (CiViUM), University of Murcia, Murcia, Spain
  • Antonio Del Águila-Carrasco
    Interuniversity Laboratory for Research in Vision and Optometry, Mixed group UVEG-UMU, Valencia-Murcia, Spain
    Department of Optics, and Optometry, and Vision Sciences, University of Valencia, Valencia, Spain
  • Robert Iskander
    Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
  • Norberto Lopez-Gil
    Vision Science Research Group (CiViUM), University of Murcia, Murcia, Spain
  • Footnotes
    Commercial Relationships   Maciej Bartuzel, None; Ivan Marin-Franch, None; Antonio Del Águila-Carrasco, None; Robert Iskander, None; Norberto Lopez-Gil, None
  • Footnotes
    Support  PRELUDIUM/ 2015/17/N/ST7/03814, National Science Centre (Poland) to MMB. Atracció de Talent (UV-INV-PREDOC14-179135), Universidad de Valencia to AA-C.
Investigative Ophthalmology & Visual Science June 2017, Vol.58, 5632. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Maciej Marcin Bartuzel, Ivan Marin-Franch, Antonio Del Águila-Carrasco, Robert Iskander, Norberto Lopez-Gil; Defocus vibrations improve visual resolution of defocused targets. Invest. Ophthalmol. Vis. Sci. 2017;58(8):5632.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : To test the hypothesis that rapid step changes in defocus for an out-of-focus retinal image increase visual resolution.

Methods : Visual acuity (VA) of 5 subjects (37 ± 12 y.o.) was measured under monocular conditions with a Freiburg VA test using a microdisplay that showed a high-contrast black Landolt-C letter on a white background. The text was presented at the subject’s far point or 1.00 D beyond it. VA was also measured when the target was at 1.00 D beyond the far point and longitudinal vibrations in defocus were added with different amplitudes. The longitudinal vibrations were generated as step changes at 50 Hz with a deformable mirror in a custom adaptive optics system (MurciAO) and with amplitudes of 0.25, 0.50, 0.75, and 1.00 D. In all trials, the Freiburg VA test was performed using a microdisplay that was seen through a 4-mm artificial pupil. Five repeated measurements were obtained under each viewing condition.

Results : VA of the defocused target improved as the tested amplitude of vibrations increased. Figure shows an example of the object photographed through the optical system by a camera with an exposure time of 1/6 s. Mean logMAR was −0.14 ± 0.07 at the far point, 0.35 ± 0.16 at 1 D beyond the far point and in between these two values when defocus vibrations were generated. More precisely, mean logMAR values were 0.26, 0.22, 0.10, and 0.02 for defocus vibrations with amplitudes of 0.25, 0.50, 0.75 and 1.00 D, respectively. Linear regression analysis showed a negative statistically significant (R2 = 0.59 ± 0.17, all p < 0.01) slope of VA with respect to the amplitude of vibrations that ranged between −0.16 and −0.41 logMAR units per D of amplitude.

Conclusions : Visual resolution of defocused targets improves with defocus vibrations. Our study confirms that the theoretical result predicted by Lohmann and Paris (App. Opt. 1965) is applicable to the human eye. The results add more insight into the role of wavefront dynamics in the human eye.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

 

Figure. Landolt C eye chart seen through the system in focus (left), with 1 D of defocus (middle), and with 1 D of defocus with vibrations of 1 D of amplitude.

Figure. Landolt C eye chart seen through the system in focus (left), with 1 D of defocus (middle), and with 1 D of defocus with vibrations of 1 D of amplitude.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×