A high-resolution binocular video-oculography system: assessment of pupillary light reflex and detection of an early incomplete blink and an upward eye movement

Background: The pupillary light reflex characterizes the direct and consensual response of the eye to the perceived brightness of a stimulus. It has been used as indicator of both neurological and optic nerve pathologies. As with other eye reflexes, this reflex constitutes an almost instantaneous movement and is linked to activation of the same midbrain area. The latency of the pupillary light reflex is around 200 ms, although the literature also indicates that the fastest eye reflexes last 20 ms. Therefore, a system with sufficiently high spatial and temporal resolutions is required for accurate assessment. In this study, we analyzed the pupillary light reflex to determine whether any small discrepancy exists between the direct and consensual responses, and to ascertain whether any other eye reflex occurs before the pupillary light reflex. Methods: We constructed a binocular video-oculography system two high-speed cameras that simultaneously focused on both eyes. This was then employed to assess the direct and consensual responses of each eye using our own algorithm based on Circular Hough Transform to detect and track the pupil. Time parameters describing the pupillary light reflex were obtained from the radius time-variation. Eight healthy subjects (4 women, 4 men, aged 24–45) participated in this experiment. Results: Our system, which has a resolution of 15 microns and 4 ms, obtained time parameters describing the pupillary light reflex that were similar to those reported in previous studies, with no significant differences between direct and consensual reflexes. Moreover, it revealed an incomplete reflex blink and an upward eye movement at around 100 ms that may correspond to Bell’s phenomenon. Conclusions: Direct and consensual pupillary responses do not any significant temporal differences. The system and method described here could prove useful for further assessment of pupillary and blink reflexes. The resolution obtained revealed the existence reported here of an early incomplete blink and an upward eye movement.

Contract for the great College, 6 May 1813

This is a contract signed between Loammi Baldwin, acting on behalf of the President and Fellows of Harvard College, and Josiah Moore, Esquire; John Walton, Housewright; Thomas Mason, Housewright; Samuel Mason, Housewright; and Joseph Holmes, Housewright, for the construction of University Hall. The agreement was witnessed by William Jenison and Josiah Nottage.

Contract for finding all materials and finishing interior of University Hall, signed copy, 1 February 1814

This is a contract signed between Loammi Baldwin, acting on behalf of the President and Fellows of Harvard College, and Josiah Moore, John Walton, Thomas Mason, Samuel Mason, and Joseph Holmes for completing the dining rooms and chapel of University Hall. The agreement was witnessed by Abraham Edwards and Thomas Edwards.

Contract for finding all materials and finishing interior of University Hall, 1 February 1814

Draft of the official signed copy of the contract in Box 1, Folder 42. This copy is written in a different hand and contains several struck through phrases.

Memorandum of contract with carpenters, Moore, and others, [ca. 1814]

Estimate for $5942.68 for the completion of the interior fixtures of University Hall including folding doors, pew arrangement in the chapel, and architraves to doors, windows, and fireplaces.

[Letter regarding the taxing of Harvard College real estate] (incomplete draft), [1798]

Two leaves of a draft of a letter in Eliphalet Pearson's hand addressed to "Gentleman,"detailing the Committee of the town of Cambridge's attempts to tax real estate owned the College.

An incomplete unidentified work on inheritance : manuscript, undated

بسم الله الرحمن الرحيم وبه الاعانة فصل اعلم ان الناظم لم يتعرض. :Incipit