Effect of monochromatic aberrations on photorefractive patterns

Area of Science:

• Ophthalmology
• Optical Engineering
• Pediatric Optometry

Background:

• Photorefractive methods are widely used for measuring refractive and accommodative states in children.
• Measurement accuracy can be compromised by monochromatic aberrations, which are difficult to predict and control.
• Existing optical analyses do not fully account for the impact of monochromatic aberrations on photorefraction.

Purpose of the Study:

• To define and quantify the measurement uncertainty introduced by monochromatic aberrations in photorefractive methods.
• To extend paraxial optical analyses to better predict the effects of aberrations on photorefractive measurements.
• To explore the potential for photorefraction to simultaneously measure refractive state and ocular aberrations.

Main Methods:

• Extended paraxial optical analyses of coaxial and eccentric photorefraction.
• Incorporated reported amounts of spherical aberration (SA) and coma for human eyes.
• Calculated predicted photorefractive patterns for various monochromatic aberration levels and types.

Main Results:

• Monochromatic aberrations, particularly spherical aberration, introduce significant uncertainty in photorefractive measurements.
• The calculated dioptric uncertainty may exceed the eye's actual spherical aberration.
• Significant effects were observed for a combination of spherical aberration and coma in a model eye.

Conclusions:

• Photorefractive methods are susceptible to significant errors from monochromatic aberrations.
• The developed optical analysis can predict the impact of aberrations on photorefractive patterns.
• This may enable future extensions of photorefraction for simultaneous refractive and aberration measurements.