ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1990.tb01096.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Demonstrating stereopsis is valuable in vision screening of infants and toddlers, since its presence rules out the possibility of profound visual deficits. We assessed the performance of 55 infants and young children on three clinically available tests, the Lang, the Frisby and the TNO. The results were compared with those found using a computerized dynamic random dot stereogram.Most of the children tested were under 3 years of age and 10 were aged under 1 year. The Lang test was passed by 74%, including 50% of those under 1 year. The Frisby test was passed by 65%, but by only 20% of infants under 1 year. Forty‐nine per cent passed the TNO test; none were under 1 year. The computerized stereogram was passed by 42.5% of those tested, including 100% of those over 3 years old. Both this test and the TNO presented difficulty in testing infants between 8 months and 2 years because of the increased likelihood that these children would reject the red/green glasses.We recommend that the most appropriate stereotest is largely based on whether the child will tolerate red/green glasses. We would use the dynamic random dot test for infants under 8 months of age, the Lang or Frisby stereotest for infants from 8 months to 30 months, and the TNO or dynamic random dot stereogram after this ag

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1990.tb01097.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

An open low vision clinic has been in operation at University of Wales College of Cardiff, Department of Optometry for 5 years. This paper describes the demography and visual characteristics of 218 consecutively presenting patients. A detailed survey of the aids prescribed is conducted. A significant proportion of low vision patients required only simple aids (56.8%) and low magnification (71.6%). It is suggested that these patients could be assisted in an optometric practice.In addition, visual acuity, distance or near is not a good indicator of eventual visual performance with an LVA. Therefore, it was concluded that all patients having measurable form vision should receive a low vision assessment.

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1990.tb01098.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Numerous reasons have been cited for patient non‐tolerance to Progressive Addition Lenses (PALs). This paper considers two presbyopic subject populations‐those who successfully wore PALs (n = 20), and those who were non‐tolerant to them (n = 18). The dispensing accuracy of the PALs worn by subjects was assessed and the surface quality of those lenses worn by unsuccessful patients studied. These factors do not account for any significant differences between the two groups, suggesting that other causes must separate the subject popula

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1990.tb01099.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Normative contrast sensitivity (CS) data were obtained using the commercially available Pelli‐Robson chart from the dominant eye of 30 young (mean (±SD) age 22.5 ± 4.3 years) and 42 older (mean (±SD) age 70.2 ± 6.7 years) subjects with normal healthy eyes. The majority of young subjects were found to have a CS of 1.80 log units or above. The majority of the older subjects were found to have a CS of 1.65 log units or above. CS results were obtained using both sides (A and B) of the Pelli‐Robson chart from 30 (15 young and 15 older) of these subjects. These measurements were repeated under identical conditions, 2 weeks later. There was no significant difference between the results from sides A and B of the chart. The CS scores were shown to be repeatable to within ±0.15 log units or ±1 step. Therefore a significant change in CS score is +2 steps or 0.30 log units. Slight improvements in reliability could be obtained by more careful permutation of letters on each step and a smaller step size. The restriction against these changes is the ensuing increased c

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1990.tb01100.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Horizontal fusional limits and lateral phorias were measured subjectively on five normal subjects after adaptation to increments of base‐in and base‐out prism. Both the phoria and the fusional limits were found to change by approximately the amount of the adapting prism. The fusional amplitudes (the difference between the phoria and the fusional limits) were relatively unaffected by vergence adaptation except at the largest values of adapting prism. These results are in agreement with current models of disparity vergence eye movement control which suggest that there are independent fast and slow fusional vergence mechanisms, each with its own saturation li

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1990.tb01101.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Prism adaptation responses in orthophoric, exophoric and esophoric subjects are compared and found to be significantly different. Following a prolonged period of monocular occlusion the prism adaptation responses were compared, after occlusion the differences are no longer significant. This supports the theory that vergence (prism) adaptation is responsible for the existence of heterophoria. This paper shows that changes in heterophoria with monocular occlusion are caused by desaturation of prism adaptation.

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1990.tb01102.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The monocular contrast sensitivity loss with defocus is well known. We measured binocular contrast sensitivity of sinewave gratings of 6 c/deg in the presence of different levels of monocular defocus. In the absence of defocus, the binocular sensitivity was about 42% higher than monocular. With increasing monocular defocus, the binocular sensitivity decreased steadily until it reached a level below the monocular, showing binocular inhibition. The clinical implications of binocular inhibition with monocular defocus are discussed.

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1990.tb01103.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Glare disability plays an important part in the investigation and assessment of cataract. We investigated the effect of monocular glare disability on binocular contrast sensitivity. The magnitude of binocular summation was measured at different degrees of monocular glare disability. In the absence of glare, maximum binocular summation was shown. With increasing glare disability, the degree of binocular summation decreased steadily until binocular inhibition was produced. Binocular inhibition is defined as a reduction in binocular sensitivity to reach a level below the monocular. The clinical implications of binocular inhibition with monocular glare disability are discussed.

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1990.tb01104.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The Adams desaturated D‐15 was designed to be administered to patients with acquired colour vision defects by simply reducing the chroma of the Munseli colours by 2 for each cap in the test. In this study, the performance of the Adams desat D‐15 in the assessment of congenital colour vision deficiencies is evaluated. The standard D‐15 and Adams desat D‐15 tests were administered to 75 congenital red‐green colour deficient subjects who had been diagnosed on the basis of their performance on the Nagel anomaloscope Mark 1. The results were analysed in terms of the direction, extent and specificity of errors and compared with the diagnosis on the Nagel anomaloscope. Of the 13 colour‐deficient subjects who made no errors on the standard D‐15, 1 failed the Adams desat D‐15 and 2 made single crossings. No colour‐deficient subject who failed the standard D‐15 made anything less than a simple inversion of adjacent caps on the Adams desat D‐15. The Adams desat D‐15 did not perform as well as the standard D‐15 in identification of the type of defect in dichromats. On the basis of these data, it is predicted that about 5% of dichromats will be mis‐classified by the Adams desat D‐15 whilst under 0.1% will be mis‐classified by the standard D‐15. However, with the anomalous trichomats, more crossings were made on the Adams desat D‐15, particularly by the milder anomals, and a diagnosis was possible in more cases. Where a diagnosis was possible, it was also correct more often with the Adams desat D‐15. The Adams desat D‐15 provides a useful sub‐classification of those who pass the standard D‐15. A choice of Munseli colours lying on confusion lines rather than by a simple universal reduction of chroma by two steps should provide a more reliable diagnosis of typ

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1990.tb01105.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY