Heron G, Furby H P, Walker R J, Lane C S, Judge O J
Department of Vision Sciences, Glasgow Caledonian University, UK.
Ophthalmic Physiol Opt. 1995 Jan;15(1):23-30.
The visual acuities of 17 young emmetropes and corrected ametropes were measured over the range of 7.5-0.19 m using a Bailey-Lovie chart. Accommodation stimulus-response measures were also taken over this range using retinoscopy to establish whether variations in visual acuity with observation distance could be attributed to accommodation behaviour. Tonic accommodation was recorded using the Canon R1 autorefractor and was compared with visual acuity and stimulus-response results. In general, visual acuity was found to be dependent on stimulus distance, being significantly reduced for most observers for the closest targets. There were three categories of observer performance for visual acuity as a function of observation distance; one group showing no change in visual acuity with distance, a second showing a flat function for distances 7.55-0.5 m, and then a decrease in visual acuity for shorter distances; and a third category that showed a maximum visual acuity in the 1.2-1.6 m region. This behaviour was unrelated to individual stimulus-response characteristics and there was no significant relationship between tonic accommodation and the distance where acuity was best for the third category observers.
使用贝利-洛维视力表，在7.5 - 0.19米的范围内测量了17名年轻正视眼者和矫正屈光不正者的视力。在此范围内，还使用检影法进行了调节刺激-反应测量，以确定视力随观察距离的变化是否可归因于调节行为。使用佳能R1自动验光仪记录张力性调节，并将其与视力及刺激-反应结果进行比较。总体而言，发现视力取决于刺激距离，对于大多数观察者来说，最接近的目标的视力显著降低。作为观察距离函数的视力有三类观察者表现；一组视力随距离无变化，第二组在7.55 - 0.5米距离时视力呈平稳状态，然后在更短距离时视力下降；第三类在1.2 - 1.6米区域显示最大视力。这种行为与个体刺激-反应特征无关，对于第三类观察者，张力性调节与视力最佳时的距离之间没有显著关系。
