Structured light enhanced entoptic stimuli for vision science applications

Abstract

The dichroic macular pigment in the Henle fiber layer in the fovea enables humans to perceive entoptic phenomena when viewing polarized blue light. In the standard case of linearly polarized stimuli, a faint bowtie-like pattern known as the Haidinger's brush appears in the central point of fixation. As the shape and clarity of the perceived signal is directly related to the health of the macula, Haidinger's brush has been used as a diagnostic marker in studies of early stage macular degeneration and central field visual dysfunction. However, due to the weak nature of the perceived signal the perception of the Haidinger's brush has not been integrated with modern clinical methods. Recent attempts have been made to increase the strength of the perceived signal by employing structured light with spatially varying polarization profiles. Here we review the advancements with the structured light stimuli and describe the current challenges and future prospects.

Conditions on detecting tripartite entangled state in psychophysical experiments

“…In this line of work, the researchers successfully utilized R and L polarization coupled orbital angular momentum (OAM) states with an azimuthal phase dependence to trigger the entoptic vision of the human subject in which the number of visible azimuthal fringes become proportional to the difference in the OAM values [49,50]. Utilizing OAM structured light has shown promise as humans were able to distinguish OAM states with high accuracy and it was argued that one can use such states for diagnosis of macular degeneration, as the number of observed fringes would be different between healthy and unhealthy subjects [51,52]. Although using such states is an interesting research direction to investigate entanglement sensitivity of the human visual system, challenges exist in adapting such techniques to our proposed experimental scheme.…”

Visual Snow Syndrome in Patient with Migraine: Case Report and Literature Review

“…This is known as Haidinger’s brush. The condition of the macula is directly related to the shape and clarity of the perceived signal [ 27 ]. The enhanced entoptic phenomenon is a visual disorder that results from the structure of the visual system itself.…”