Abstract
In 54.2% of glasses inadequate frame are prescribed and in 70.9% of glasses lenses of incorrect dioptor are prescribed in Japan. Especially 31.9% of glasses are corrected over 1.0 diopter. It is noteworthy that most of them are prescribed without ophthalmological medical care. Incomplete subjective examination and no objective examination are the major causes for the prescription of these inadequate glasses in Japan. In subjective examination of refractive anomalies binocular fogging and checking astigmatism under fog are indispensable to avoid accommodative spasm. Not only refractometer but retinoscopy is also necessary for objective examination.
Using new subjective method (subjective method 2) instead of ordinal method (method 1) we can obtain fairly good accordance between total astigmatism and corneal astigmatism. Correlation coefficient between total astigmatism and corneal astigmatism is only 0.006 by using method 1, but 0.496 by using method 2, i.e., the latter indicates fairly good correlation. Therefore, ophthalmometry is also necessary to prescribe good glasses, especially in the cases whose axis of total astimatism do not coincide with that of corneal astigmatism.
Dioptor of prescribed glasses is not always consistent with the result of refractive examinations. Using the test for near vision and binocular vision, and observations of whole clinical course, a major error of making inappropriate glasses might be abolished. we call this 4-dimensional prescription.
In Japan, 36% of total populations are using glasses and population using glasses for far vision will be ca 22 millions (20.5%). As described above, about 30% of these, i.e. 6.6 millions of people are using markedly inadequate glasses. This relates closely to the fact that 76.9% of glasses which must be prescribed under ophthalmological medical care, has been made only by opticians who have no official licenses.
