Scientists develop new technique that reduces halo effect caused by lenses

In a recent study published in Optics Communications, scientists from Bar-Ilan University in Israel have presented a new technique that significantly reduces the halo effect that is generated when using multifocal (contact and intra-ocular) lenses and looking at bright point sources in dark conditions.

Presbyopia is a result of natural aging and stems from a gradual thickening and decrease in elasticity of the lens inside the eye. Corrective lenses used to address presbyopia often lead to a . This is basically a glow or color light pattern observed when looking at a bright source of light in front of a dark background. It is mostly experienced at night when people see halos around street lamps and car headlights, and it can make driving at night unsafe or even impossible in extreme cases.

Co-author of the paper, Prof. Zeev Zalevsky, head of the Electro-Optics study program of the Faculty of Engineering at Bar-Ilan, explains, "Our solution involves smoothening the surface structure of a or an intra-ocular lens that has extended depth of focus or multifocal capabilities. The smoothening does not complicate the fabrication complexity of the lens and yet yields the same optical performance in treating presbyopia and assisting people after cataract surgery, but with about one order of magnitude smaller. This allows people that use such lenses to be able to use them also at night."

More and more commercial ophthalmic products incorporate EDOF (extended depth of focus) and multifocal technologies in contact and intra-ocular lenses to solve . Until now, such were very problematic when used in dark illumination conditions. The researchers say their proposed concept can resolve the above difficulties and make the existing products even more applicable and useful.


Explore further

Multifocal contact lenses may reduce vision for night driving

More information: "Ophthalmic halo reduced lenses design" by Ofer Limon and Zeev Zalevsky. DOI: 10.1016/j.optcom.2014.12.049
Provided by Elsevier
Citation: Scientists develop new technique that reduces halo effect caused by lenses (2015, April 15) retrieved 21 April 2019 from https://phys.org/news/2015-04-scientists-technique-halo-effect-lenses.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
524 shares

Feedback to editors

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more