摘要:

The education and training of optometrists-more appropriately, ophthalmic opticians -in the western countries of the European continent differ in content and amount from that found in English-speaking countries, particularly the U. S. Current curriculum patterns for 12 European countries are presented. Formalized basic education before professional training averages 9.4 academic years; formalized course work, identified with curricula of schools of optics and optometry, averages 2.8 academic years; and required apprenticeship time averages about 2 years.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Oxygen tension under a hard, gas-permeable contact lens is calculated. The gas permeability of the lens is taken from the engineering literature and is shown to be 10 times smaller than claimed in the optometric literature. The engineering data are supported by new measurements of gas permeability. Calculations using the new data show that the oxygen tension under the lens is at the lower end of the range of acceptable values.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Six subjects were fitted binocularly with both nonprism and prism-ballast spherical Hydrocurve(tm) contact lenses to evaluate lens rotation on toric corneas. The 1 Δ and the 1 Δ lenses rotated significantly less than the equivalent nonprism lenses. For 11 of 12 eyes, V2 A was sufficient to stabilize the lens.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

In simultaneous border contrast enhancement, a border formed by an abrupt luminance discontinuity is perceptually enhanced on the bright side by a band of greater brightness and on the dark side by a band of greater darkness. The width of these perceived bands is very sensitive to small changes in the retinal image quality. This study explored the effect of contact lenses of varying steepness on the border enhancement spread. It was found that, over time, the effect of a contact lens on this spread generates a characteristic function. Furthermore, certain features of this function reflect the degree of steepness of the contact lens. It is suggested that the most important factors determining this function are tear flow and scatter-producing corneal edema.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Different dyes were used to tint Soflens contact lenses. The light transmission of each lens was measured before and after tinting and after asepticizing it in fresh saline from 1 to 15 times. Crystal violet was found to be the dye most stably retained within the lens after saline asepticizing. By asepticizing hydrophilic lenses in solutions of food coloring, we found that the amount of dye retained by a lens was not cumulative and the transmittance was maintained at approximately the original value. Tests of these tinted lenses for toxicity to animals or human subjects were not performed, nor did we ascertain whether these dyes affect the durability or hydrophilic and wetting properties of these lenses.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Fifteen normal and 18 red-green-deficient subjects were tested with the Farnsworth Dichotomous Test of color vision (Panel D-15) and with an alternative version of the dichotomous test consisting of selected color chips from the Farnsworth-Munsell 100-Hue Test. Results indicate that the 100-Hue version of the dichotomous test is equivalent to the standard Panel D-15 with respect to detecting and differentiating among the more severe red-green deficiencies. These results confirm A. Pinckers' previous suggestion that the 100-Hue Test contains the components necessary for a Farnsworth Panel D-15.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

The Roth 28-hue test, first described in 1966, uses every third color cap from the Farnsworth-Munsell 100-hue (85-color-cap) test. Protans, deutans, and tritans exhibit slightly different confusion axes on the Roth 28-hue test and the Farnsworth D-15 test. These axes are illustrated on a CIE chromaticity diagram. The little-used Roth 28-hue test may be a good compromise between the D-15 and 100-hue tests, but clinical trials for verification are needed.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Visual acuity of persons aged 16 to 90 years was measured with Snellen letters of varied contrast at 10, 1, 0.1, and 0.01 fL chart luminances. Percentage losses of seeing with age were computed. At 10 fL luminance, perception of high- and medium-contrast letters has changed little at age 40, but about twice as much light is needed to see low-contrast letters as at age 20. By age 70, no 2-min-subtense (20/40) letters were seen at 0.01 fL luminance. The need of older people for increased lighting during indoor tasks and night driving is discussed.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID