Using pattern classification to measure adaptation to the orientation of high order aberrations

Area of Science:

• Ophthalmology
• Vision Science
• Computational Neuroscience

Background:

• Ocular aberrations cause image blur specific to each individual's eye.
• Previous research indicates the eye adapts to the level of blur from high-order aberrations (HOA).
• This study investigates if visual coding also adapts to the orientation of natural HOA.

Purpose of the Study:

• To determine if visual perception adapts to the orientation of an individual's natural high-order aberrations (HOA).
• To explore the specificity of the internal blur code in human vision.

Main Methods:

• A psychophysical procedure inspired by Classification Images was used.
• Subjects judged perceived blur from images artificially blurred with HOA from 100 real eyes.
• Adaptive Optics corrected subjects' natural aberrations during image presentation.

Main Results:

• Positive responses (best focused images) correlated significantly with the subject's natural Point Spread Function (PSF) orientation.
• Negative responses (less focused images) showed a near-perpendicular orientation to the natural PSF.
• Four out of five subjects demonstrated a bias in their blur perception aligned with their natural PSF orientation.

Conclusions:

• The Classification-Images technique effectively identifies internally coded blur.
• Internal blur coding appears specific to individual high-order aberrations.
• Blur normalization mechanisms utilize orientation cues from natural aberrations.