{"id":342,"date":"2026-01-24T03:30:36","date_gmt":"2026-01-24T03:30:36","guid":{"rendered":"https:\/\/www.jeffnathanson.com\/NateHart\/?page_id=342"},"modified":"2026-01-24T21:49:16","modified_gmt":"2026-01-24T21:49:16","slug":"high-precision-eye-tracking","status":"publish","type":"page","link":"https:\/\/www.jeffnathanson.com\/NateHart\/high-precision-eye-tracking\/","title":{"rendered":"High-Precision Eye-Tracking"},"content":{"rendered":"\n<p>Over the summer I participated in the 2025 Photonics REU at the University of Rochester. I worked under Professor Jannick Rolland with PhD Student Anis Idrizovi<em>\u0107<\/em> on developing a high-precision eye-tracker. As this work has not yet been published I&#8217;ll refrain from getting into the specifics. However, I&#8217;ll detail the specific eye-tracking method used, called <strong>Dual Purkinje Imaging<\/strong>. <\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Dual Purkinje Imaging<\/h2>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" src=\"https:\/\/www.jeffnathanson.com\/NateHart\/wp-content\/uploads\/2026\/01\/IMG_7754-1024x768.png\" alt=\"\" class=\"wp-image-343\" srcset=\"https:\/\/www.jeffnathanson.com\/NateHart\/wp-content\/uploads\/2026\/01\/IMG_7754-1024x768.png 1024w, https:\/\/www.jeffnathanson.com\/NateHart\/wp-content\/uploads\/2026\/01\/IMG_7754-300x225.png 300w, https:\/\/www.jeffnathanson.com\/NateHart\/wp-content\/uploads\/2026\/01\/IMG_7754-768x576.png 768w, https:\/\/www.jeffnathanson.com\/NateHart\/wp-content\/uploads\/2026\/01\/IMG_7754-1536x1152.png 1536w, https:\/\/www.jeffnathanson.com\/NateHart\/wp-content\/uploads\/2026\/01\/IMG_7754-2048x1536.png 2048w, https:\/\/www.jeffnathanson.com\/NateHart\/wp-content\/uploads\/2026\/01\/IMG_7754-1568x1176.png 1568w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">A picture of my own eye where P1 (bright spot bottom left) and P4 (top right spot) are visible. You can also see P2 out of focus next to P1.<\/figcaption><\/figure>\n\n\n\n<p>By shining a collimated beam at the eye, the light will reflect off of both the front and back surfaces of the cornea and lens. These partial reflections are called Purkinje Images and we utilize the first and fourth of these images, dubbed P1 and P4. Fortunately, P1 and P4 lie in approximately the same focal plane and their relative position is roughly linear with eye rotation. Thus by just tracking the positions of P1 and P4, one can back out how much the eye has rotated and then what the observer is looking at (given some reference point).<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Over the summer I participated in the 2025 Photonics REU at the University of Rochester. I worked under Professor Jannick Rolland with PhD Student Anis Idrizovi\u0107 on developing a high-precision eye-tracker. As this work has not yet been published I&#8217;ll refrain from getting into the specifics. However, I&#8217;ll detail the specific eye-tracking method used, called [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-342","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.jeffnathanson.com\/NateHart\/wp-json\/wp\/v2\/pages\/342","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.jeffnathanson.com\/NateHart\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.jeffnathanson.com\/NateHart\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.jeffnathanson.com\/NateHart\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.jeffnathanson.com\/NateHart\/wp-json\/wp\/v2\/comments?post=342"}],"version-history":[{"count":3,"href":"https:\/\/www.jeffnathanson.com\/NateHart\/wp-json\/wp\/v2\/pages\/342\/revisions"}],"predecessor-version":[{"id":373,"href":"https:\/\/www.jeffnathanson.com\/NateHart\/wp-json\/wp\/v2\/pages\/342\/revisions\/373"}],"wp:attachment":[{"href":"https:\/\/www.jeffnathanson.com\/NateHart\/wp-json\/wp\/v2\/media?parent=342"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}