Human pupil measurement

Keywords— Human pupil measurement, pupil recognition, biometric fleld. Graphical User Interface, iris recognition. 

Fig. 8 Graphical User Interface (GUI) of human pupil measurements...

Measurement of the Area and Diameter of Human Pupil Using Matlab... 

The experiments involve five samples of human pupil downloaded from CASIA Ms Image Database from different person in order to observe the result. Table 1 shows the results of area and diameter measurements for 5 pairs of eyes that had been obtained. 

The course of post-LSD pupillary changes, with respect to dosage schedule and intensity and duration of effects, is a valuable tool. Pupil size 3 hr after the initial dose responded to the second dose of LSD and was an obvious measure to track in acute tolerance studies in humans. Given the number of rat studies in which this would be useful to monitor, the problem lies in determining rat mydriasis (easy in other animals) while a computerized pupillometer (developed by Martin Adler at Temple University) was informally tried by us once with LSD, systematic studies have not been done. 

Entopic pupillometry is an accurate and practical method for measuring the size of the pupil in humans (53). With a Cogan entopic pupillometer, the normal size of the pupil and the near and far points before and after instillation of the drug in the conjunctival sac can be measured at different time intervals. The amount of light entering the eye is quite small and the movements of the eye during the measurement do not interfere with the test. 

In humans, the adult eyeball measures approximately one inch (2.5 centimeters) in diameter, and of its total surface area, only the anterior one-sixth is exposed to the external environment. This exposed area is protected by accessory structures of the eye, including the eyelids, eyelashes, eyebrows, lacrimal (tearing) apparatus, and extrinsic eye muscles. Each eyelid possesses a conjunctiva, which is a thin, transparent, and protective mucus membrane. The conjunctiva lines the inner aspect of the eyelids as the palpebral conjunctiva and folds back (reflects) over the eyelids onto the anterior exposed surface of the eyeball as the bulbar (ocular) conjunctiva. The bulbar conjunctiva covers only the white of tlae eye (not the cornea that covers over the iris and pupil). Because tlie bulbar conjunctiva is quite thin, blood vessels are clearly visible beneath it. When these blood vessels are dilated and congested from local irritation or infection (conjunctivitis, or inflammation of the conjunctiva), the result is the appearance of reddened and irritated bloodshot eyes. 

The inherent nonlinearity between the physically measurable state of a control room environment and the comfortable subjectively felt state of it is ameliorated by the fact that most felt states exist not as points but as ranges. Because the human body is able to regulate itself, comfort, health, and performance can be sustained over a comparatively wide range of physical values. It is important to note that this regulatory characteristic is both physiological (e.g., pupils dilate in darker conditions. 

---