Eye References In The Homeric Epics
Rapport named this substance serotonin; it is manufactured quite profusely by specialized cells lining the wall of the gut, and it is presumed to play a role of some kind in the peristaltic movements. The human eye contains enough complexity to warrant specialized attention and care beyond the duties of a general practitioner. These specialists, or eye care professionals, serve different functions in different countries. Eye care professionals can have overlap in their patient care privileges. For example, both an ophthalmologist (M.D.) and optometrist (O.D.) are professionals who diagnoses eye disease and can prescribe lenses to correct vision. However, typically only ophthalmologists are licensed to perform surgical procedures.
In fact, he could find no use whatever for melatonin in the body economy of mammals. They discovered the basic biochemical sequences performed by the pineal in the manufacture of melatonin; they found that it was produced from serotonin by the action of two enzymes, an acetylating enzyme and a methoxylating enzyme. By blocking or augmenting the action of these enzymes, Axelrod and his assistants were able, most ingeniously, to stimulate or suppress the organism’s own manufacture of melatonin. In the course of this work, it became apparent that Otto Heubner’s old contention that the pineal produced a substance which interfered with sexual development was very close to the truth.
Some of the literature describes attacks, sudden, spontaneous, and totally unexpected, like that attack which overcame St. Paul on the road to Damascus. Reports of these kinds of exalted states have come to us not only through the literature of religious fanaticism; such accomplished scientists as Pascal and Newton have written of being overcome by mystic trances to which they attribute many of their creative insights. William James well understood that the mystic was often able to effect an almost miraculous synthesis between this world of “imagined” reality and the world of phenomena. In recent years, psychology has tended, to its discredit, to ignore these elements of William James’s thought.
Several suspected causal factors in our environment have been studied so far. One hypothesis is that indoor air pollution may cause eye and airway irritation. Eye irritation depends somewhat on destabilization of the outer-eye tear film, in which the formation of dry spots on the cornea, resulting in ocular discomfort.
The adjustment to close-range vision involves three processes to focus an image on the retina. Some irregular drifts, movements smaller than a saccade and larger than a microsaccade, subtend up to one tenth of a degree. Martin Rolfs states that ‘the majority of microsaccades observed in a variety of tasks have amplitudes smaller than 30 min-arc’. However, others state that the “current consensus has largely consolidated around a definition of microsaccades that includes magnitudes up to 1°.” This ensures that individual photosensitive cells are continually stimulated in different degrees. Without changing input, these cells would otherwise stop generating output.