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1 minuut google scholar:
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Reported ocular effects of cannabis include abnormalities of eye movements and effects on pupil size and reaction to a light stimulus.1 However the effect of cannabis on pupil size is controversial. Hepler2 examined the pupils before smoking (2g of cannabis in a 30min period using an ice-cooled pipe with a tetrahydrocannabinol (THC) concentration 1.5%) and at intervals of 5, 60, 150 and 300min after smoking and demonstrated that the pupils tend to constrict slightly soon after smoking cannabis. Green3 has stated that pupillary dilation is often erroneously attributed to cannabis and suggests that this response is usually noted by law enforcement personnel and is more likely a product of fear. Certainly a report4 with guidelines for doctors on the physical findings following cannabis states that the pupil size may be normal or dilated.
In another study where 12 healthy volunteers inhaled a joint containing 40mg THC within 10min5 pupil size was measured before dosing as well as at 40 and 80min. The pupil diameter tended to decrease during THC impairment. Other research has shown that after a dose of 3.9% THC the pupil diameter decreased in size with a peak response at 30min.6
Stark, M. M., Englehart, K., Sexton, B. F., Tunbridge, R., & Jackson, P. (2003). Use of a pupillometer to assess change in pupillary size post-cannabis. Journal of clinical forensic medicine, 10(1), 9-11.
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The effect of THC on the pupillary reaction is discussed controversially. In some police training manuals wide and sluggish pupils are described as reliable signs of the influence of THC. Some authors, who measured pupil size during THC influence observed reduced pupillary diameters. Only when a non-physiological dosage was administered in rats, a dose-related mydriasis could be detected. The aim of the present study was to characterise the effect of THC on the human pupil. 7 healthy volunteers inhaled a joint containing 40 mg hashish within the following 10 minutes. The experiments were carried out before the THC consumption as well as 40 min. and 80 min. after smoking. Pupil size and the pupillary light reflex after a short light stimulus (4 different intensities) were registered by means of the JR-videopupillography device CIP 8.00 (AMTech, Weinheim). The latency of pupillary constriction remained unchanged by THC. When compared with the sober state, a reduced pupil diameter could be observed during THC influence. Also the amplitude of pupillary constriction after the light stimulus was slightly lower under the influence of THC. In accordance with Hepler et. al (3) effects caused by THC, such as reduced amplitude of pupillary constriction, increased heart rate and reduced lacrimation, as well as salivation can be characterised as atropine-like or parasympatholytic effects.
Priemer, F., Gappmaier, A., Ruby, M., Sachs, H., Tutsch-Bauer, E., Peschel, O., & Eisenmenger, W. (1999). The effect of THC on the pupillary reaction. Blutalkohol, 36(2), 84-98.
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In an experiment using ten subjects, marijuana produced a dose-related constriction of the pupil
Brown, B., Adams, A. J., Haegerstrom-Portnoy, G., Jones, R. T., & Flom, M. C. (1977). Pupil size after use of marijuana and alcohol. American journal of ophthalmology, 83(3), 350-354.
Ik ben blij dat dit misverstand nu uit de wereld is
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