Size of pupils

Opalescent areas, no details of iris visible, size of pupil barely discernible 3... 

Easily discernible translucent areas of opacity (details of iris slighUy obscured) +3 = Areas of opacity, no details of iris visible, size of pupil barely discernible +4= Complete corneal opacity, iris not discernible... 

From the observation, different people have different area and diameter of the pupil. For example, the highest size of pupil based on area and diameter is obtained from the eyes of person D. The radius of the pupil is unique for each person and the right and left eyes are also having slightly different measurement. The size of pupil is also based on the light intensity. 

When a patient is scheduled for eye surgery, it is most important that the eye drops ordered by the primary health care provider are instilled at the correct time. This is especially important when the purpose of the drug is to change the size of the pupil. 

We have developed another bench for the measurement of the contrast value. Contrast measurement have been carried out on the MMA fabricated by Texas Instrument, in order to establish the test procedure (Zamkotsian et al., 2002a Zamkotsian et al., 2003). We can address several parameters in our experiment, as the size of the source, its location with respect to the micro-elements, the wavelength, and the input and output pupil size. In order to measure the contrast, the micro-mirrors are tilted between the ON position (towards the spectrograph) or the OFF position (towards a light trap). Contrast exceeding 400 has been measured for a 10° ON/OFF angle. Effects of object position on the micro-mirrors and contrast reduction when the exit pupil size is increasing have also been revealed. 

However this technology has also some limitation. For example, pupil diameter is an overall parameter and for a 100 m primary telescope, the internal pupil diameter cannot be reduced below 1 m. According to the maximal size of the wafers (8 inches), a deformable mirror based on MOEMS technology cannot be build into one piece. New AO architectures are under investigation to avoid this limitation (Zamkotsian and Dohlen, 2001). 

Spatial resolution is a function of altitude of the backscattering region Hi, since the size of the defocus image writes D Hj — Hi)/ HfHi). With Hf 25km and Hi =11 km and if the spot is observed with a resolution of 1 arcsec, then when projected to the pupil the resolution is 5 x Hf Hi)/ Hf — Hi) 0.26m. At a 32 m, the defocus image is 2 arcmin wide. 

Pupil size shows only a modest increase, and takes 8 hours to peak (Fig. 49). This suggests that most of the enlargement of pupils is central in origin although, as indicated previously, there is some doubt as to the centrality of the mechanism. 

Physiological Basis of Pupil Size and the Light Reflex.128... 

PHYSIOLOGICAL BASIS OF PUPIL SIZE AND THE LIGHT REFLEX 7.2.1 Pupil Size... 

Pupil size can be estimated from direct observation. A variety of cards and scales are available whereby the experimenter compares the size of the pupil to standard patterns and scales. The simplest and most often used card is the Haab pupil gauge. This consists of a card with black circles graduated in size between 2 and 10 mm in 0.5-mm increments. The card is held on the temporal side of the eye out of the subject s vision (to reduce accommodation miosis). Pupil size can be determined to an accuracy of 0.2 mm. A disadvantage of this method is the inability to make measurements in the dark and the possibility that the subject s eyes will react to the test or its administration. 

In ordinary doses, meperidine exerts inappreciable effects on respiration and circulation. In large doses, it interferes with the facilitatory function of the pneumotaxic center and the vagal afferent impulses, thereby reducing the rate and depth of respiration. With still higher doses, meperidine produces an irregular respiratory rhythm and ultimately induces apnea. It causes relaxation of the ureter, gall bladder, and bronchi. This action is partly a direct one on the smooth muscle of these structures and, in part, a result of its anticholinergic activity. It does not affect the size of the pupil or alter the tonus of the uterus. 

Q1 The iris contains pigment cells, blood vessels and two layers of smooth muscle fibres. The papillary constrictor muscles are arranged in concentric circles round the pupil when they contract, the size of the pupil decreases. The papillary dilator muscles are arranged radially away from the edge of the pupil. Contraction of these muscles widens, or dilates, the pupil. Both sympathetic and parasympathetic neurones supply and control the function of the muscles in the iris. 

Patients with unequal size of the pupils because of local causes have a painful red eye with a small pupil and suffer visual disturbances (photophobia). 

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