| 摘要 |
<p>Reading spectacles (1) having lenses (2) are provided with opaque removable films (3) over each lens. Each film (3) is provided with a small aperture (4) aligned with the optical center of the respective lens. A user may test the spectacles by wearing them and attempting to read. If the lens optical centres are not sufficiently aligned with the optical centres of the eyes, having regard to acceptable deviations in accordance with lens strength, then the effect of the restricted field of view through the apertures will be to make reading difficult. If the spectacles are acceptable, the films (3) can be removed by means of tabs (5) and the spectacles then used normally.</p> |
