Eye References In The Homeric Epics
Strong suspicion has fallen now on serotonin as being one of the principal agents of the psychedelic experience, but whatever its role, it is certain that other neurohumors are additionally involved in the chemical transactions which produce the state. It is likely that LSD itself produces certain effects quite on its own. Studies made with tracer elements and the electron microscope now reveal that LSD strikes like a chemical guerrilla, entering into receptor granules in brain cells swiftly, and then leaving swiftly after a very short time, perhaps ten or twenty minutes . This initial period coincides with the onset of the most violent symptoms of the LSD state as it is observed in test animals. But when the twenty minutes are done, and the bulk of the LSD has left the receptor granules, it is replaced by what seems to be excessive, or supernormal, amounts of serotonin. Since the LSD state lasts for some ten hours, and during this time serotonin can be measured in supernormal amounts in receptor granules, it must be considered one of the important participants of that chemical transaction which produces the state.
More detailed information about ocular albinism and oculocutaneous albinism, as well as the genetics of eye, hair, and skin color variation, is available from OMIM.org. How does the pineal perceive light, directly, by being a light sensor itself, still performing some of the functions of an eye; or indirectly, via the central nervous system? Light does penetrate bone and brain to reach the pineal in significant amounts. F. Ganong, who implanted photocells adjacent to the site of the pineal in sheep and got altered readings from his instruments depending on whether the animals were standing in direct sunlight or in shade. On the other hand, if animals are blinded, or have the nerves connecting the eye to the brain severed, some of the pineal rhythms are dampened, just as though the animals were being maintained in continual darkness.
The pineal gland produces its chemicals according to a regular oscillating beat, the basis of this beat being the so-called circadian rhythm. This pulse remains constant if darkness and light follow one another through the course of the day in a regular alternation. They found that the pineal responded somehow to light conditions, that by altering light conditions they could extend, contract, even stabilize the chemical production rhythms of the pineal. The physiological site of this sixth chakra, the sahasrara, is located in the center of the forehead; it is symbolized by an eye–the so-called third eye, the inner eye, or the eye of the mind. When this eye is opened, a new and completely other dimension of reality is revealed to the practitioner of yoga.
Related eye symptoms and signs of irritation are discomfort, dryness, excess tearing, itching, grating, foreign body sensation, ocular fatigue, pain, scratchiness, soreness, redness, swollen eyelids, and tiredness, etc. These eye symptoms are reported with intensities from mild to severe. It has been suggested that these eye symptoms are related to different causal mechanisms, and symptoms are related to the particular ocular anatomy involved. Light energy enters the eye through the cornea, through the pupil and then through the lens. The lens shape is changed for near focus and is controlled by the ciliary muscle. Photons of light falling on the light-sensitive cells of the retina are converted into electrical signals that are transmitted to the brain by the optic nerve and interpreted as sight and vision.
The posterior chamber constitutes the remaining five-sixths; its diameter is typically about 24 mm (0.94 in). The iris is the pigmented circular structure concentrically surrounding the center of the eye, the pupil, which appears to be black. The size of the pupil, which controls the amount of light entering the eye, is adjusted by the iris’ dilator and sphincter muscles.