A new coronagraph that performs destructive interference between copies of the telescope pupil in which “slices” have been swapped is studied in this paper. A fourth-order “pupil-swapping coronagraph” is particularly attractive for direct imaging of extrasolar terrestrial planets: it achieves 100% throughput at 1.4l/d on a square pupil (72.5% at 1.77 on a circular pupil), is compatible with a c...

Abstract: The Behr Pupil Revisited • Three hundred and sixty-three cases of cerebral infarction were reviewed; 19 had anisocoria. Eighty percent had the larger pupil contralateral to the hemispheric lesion. The mydriasis was associated with long tract signs in all instances. If the abnormal pupil and long tract signs are not on the same side, the long tract signs are the most accurate evidence ...

This paper presents a regional analysis of the effects of educational policies implemented in Spain between 1992 and 2003, focusing specifically on school failure rates. We consider the impact of expenditure per pupil, class size, and pupil-teacher ratio on dropout rates at the end of compulsory education and on the proportion of early school-leavers in the 18-24 year age group. Our results ind...

Abstract: The Behr Pupil Revisited • Three hundred and sixty-three cases of cerebral infarction were reviewed; 19 had anisocoria. Eighty percent had the larger pupil contralateral to the hemispheric lesion. The mydriasis was associated with long tract signs in all instances. If the abnormal pupil and long tract signs are not on the same side, the long tract signs are the most accurate evidence ...

Iris segmentation is an important phase in iris recognition and identifies the accuracy of preprocessing. This paper proposes improved peak detection algorithm to locate the pupil accurately. The modified peak detection algorithm determines the optimal peak wh ich helps for pupil localization. Thresholding is done based on the peak determined. Finally canny edge detector is applied on the binar...

AIMS A prospective randomised clinical trial was set up to compare the effect of hydroxypropyl methylcellulose (Ocucoat) and sodium hyaluronate (Healonid) on pupil size and reactivity following their use in cataract surgery. METHODS Pupil measurements were recorded before and 6 weeks after surgery. RESULTS There was no significant difference between the two groups with respect to pupil size...

The effect of artificially varying the pupil size upon the pattern evoked visual response was examined in six healthy subjects and six patients with multiple sclerosis who had abnormal visual evoked responses. Slight depression of amplitude was seen whether the pupil was small or large, but the most obvious effect was a reduction of latency with a large pupil and an increase of latency with a s...

We report a rare association of Adie's tonic pupil in a patient with systemic sclerosis who was otherwise systemically stable. This paper is an effort to unravel whether the tonic pupil and systemic sclerosis are an association by chance (which may be the case) or systemic sclerosis is the source of the tonic pupil.

Video-based eye gaze detection systems are useful for eye-slaved support system for the severely disabled. The pupil center in the video image is a focal point to determine the eye gaze. Recently, to improve the disadvantages of traditional pupil detection methods, a pupil detection technique using two light sources (LEDs) and the image difference method was proposed [1]. In addition, for users...

An ophthalmic adaptive optics (AO) imaging system is especially affected by pupil edge effects due to the higher noise and aberration level at the edge of the human pupil as well as the impact of head and eye motions on the pupil. In this paper, a two-step approach was proposed and implemented for reducing the edge effects and improving wavefront slope boundary condition. First, given an imagin...