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An optical calibration system for refractometers was designed and built using a singlet lens and a translatable detector that induces spherical error, making it a simple and easy-to-use system. The system was calibrated using spectacles and then validated by correcting blurred images created by a series of ophthalmic test lenses. A linear regression model of the correction of the ophthalmic test lenses showed nearly direct correlation with an offset of 0.12 D and an R2 value of 0.9998. An updated version of the system was designed in Zemax OpticStudio with a singlet lens, which could induce spherical error accurate to that of the human eye within ≤ 0.05 D. In future work, this system will be manufactured and tested in the lab.

© 2022 Society of Photo-Optical Instrumentation Engineers (SPIE)
Development / Ideas
Patrick O’Neal and Noam Sapiens “Optical calibration system for refractometers,” Optical Engineering 61(12), 121807 (14 November 2022). https://doi.org/10.1117/1.OE.61.12.121807
Received: 6 June 2022; Accepted: 27 October 2022; Published: 14 November 2022



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Conclusions : It is possible to control accommodation by visual stimulus. The stimulus needs to maintain perception of the distance for the duration of the control period. Cognitive tasks associated with attention focus are critical in sustaining the desired accommodation level. Leading to the state of accommodation gradually, presenting dynamic and interesting stimulus, and providing appropriate color contrast are required for successful accommodation control. Size contrast should be avoided to prevent perceptual disparity. Lastly, the level of detail should be as low as possible while maintaining realism.

This is a 2020 ARVO Annual Meeting abstract.