Steel S E, Mackie S W, Walsh G
Department of Vision Sciences, Glasgow Caledonian University, UK.
Ophthalmic Physiol Opt. 1996 Mar;16(2):95-100.
One male and one female subject wore a selection of ten current spectacle frames in random order. Monocular visual fields were assessed using an Aimark perimeter in accordance with UK Driver and Vehicle Licensing Authority (DVLA) guidelines. Of the ten frames, seven plastic frames produced an absolute scotoma intruding into a 120 degrees x 40 degrees 'letterbox' area acting as a driving visual field template. Three metal frames gave a relative scotoma; however, our apparatus was too insensitive to plot these scotomata. Relevant frame and patient parameters were measured and entered into a computer program which enabled theoretical visual field defects due to a spectacle frame to be calculated. Good agreement is shown to be possible between actual and computed visual field defects. Spectacle frames can and frequently do cause visual field defects which may affect a driver's fitness to drive. Our data also show that a frame which allows an adequate field of vision at night could cause a marked visual field defect during daylight hours. A model and rule-of-thumb are given to determine the size of these potential defects and suggestions are given to minimise or eliminate them.
一名男性和一名女性受试者随机佩戴了十种当前的眼镜架。按照英国驾驶与车辆牌照局（DVLA）的指导方针，使用Aimark视野计评估单眼视野。在这十种眼镜架中，七种塑料眼镜架产生了绝对暗点，侵入了作为驾驶视野模板的120度×40度“信箱”区域。三种金属眼镜架产生了相对暗点；然而，我们的仪器过于不灵敏，无法描绘出这些暗点。测量了相关的眼镜架和患者参数，并输入到一个计算机程序中，该程序能够计算出由于眼镜架导致的理论视野缺损。实际和计算出的视野缺损之间显示出良好的一致性。眼镜架能够而且经常会导致视野缺损，这可能会影响驾驶员的驾驶适宜性。我们的数据还表明，一个在夜间能提供足够视野的眼镜架在白天可能会导致明显的视野缺损。给出了一个模型和经验法则来确定这些潜在缺损的大小，并给出了将其最小化或消除的建议。
