Search

A subjective assessment of the optical quality of the human eye may be derived from a comparison between the contrast sensitivities obtained in response to a retracted grating display and a non-refracted grating display. The former may be generated on a cathode ray tube (CRT) while the latter may be obtained with laser interference fringes observed in the Maxwellian view. With this method, the rate of decline of the contrast ratio of the optical media with increasing spatial frequency has been shown to be appreciably less than the rate of decline of the neural performance represented by the laser contrast sensitivities. However, this comparison has been based on results in response to a green CRT display and red (Helium-Neon) interference fringes. In the present study. we have confirmed this result with respect to comparisons between a green CRT display and a green laser display, although the absolute value of the contrast ratio of the optical media for the green laser display was reduced compared with values for the red laser display. [ABSTRACT FROM AUTHOR]

Investigates the first record of the root lesion nematode, Pratylenchus bolivianus Corbett, in England and Wales. Crop where the nematode is discovered; Host range of the nematode; Characteristics of the nematodes.