Mondero Nicholas E, Crotty Russell J, West Roger W
Oklahoma College of Optometry, Northeastern State University, Tahlequah, OK 74464, USA.
Optom Vis Sci. 2013 Sep;90(9):970-9. doi: 10.1097/OPX.0b013e31829d8d48.
We studied a set of Rembrandt's self-portraits to reassess a previous claim, based on measurements of the centration of his painted irises, that Rembrandt had a large exotropia.
Of the 24 self-portraits that Rembrandt painted, with significant ocular detail to give an impression of the direction of his gaze, we scanned 10; the five with the largest difference in centration between the irises and the five with the smallest difference. The right and left eyes in each image were then occluded using Photoshop to produce two additional images that gave monocular gaze. Thirty observers then judged where the portraits appeared to be gazing within the plane of their face.
Although our observers did judge a significant outward deviation for gaze between the two eyes, part of this was caused by an outward deviation from central by the presumably nonstrabismic eye. Any greater amount of outward deviation from the "strabismic" than the nonstrabismic eye can then be explained by a gaze overshoot induced by head turn, painting with a mirror, and angle kappas. In addition, Rembrandt's apparent strabismus is seen only in those portraits painted during a few years early in his career, and portraits that Rembrandt and his students produced of other presumably nonstrabismic individuals often give a similar impression of strabismus.
There are several factors that can explain why some of Rembrandt's self-portraits make him look strabismic without concluding that he actually was. Rembrandt and his students may also have painted this appearance as an artistic style.
我们研究了一组伦勃朗的自画像,以重新评估之前基于对他所画虹膜中心位置的测量而提出的一项主张,即伦勃朗患有大度数外斜视。
在伦勃朗所画的24幅自画像中,有显著眼部细节可让人了解其注视方向,我们扫描了其中10幅;虹膜中心位置差异最大的5幅和差异最小的5幅。然后使用Photoshop对每张图像中的右眼和左眼进行遮挡,以生成另外两张呈现单眼注视的图像。接着,30名观察者判断这些画像在面部平面内看起来注视的方向。
尽管我们的观察者确实判断出两只眼睛的注视存在明显向外偏斜,但部分原因是推测为非斜视的眼睛从中心向外偏斜。那么,“斜视”眼睛比非斜视眼睛更大程度的向外偏斜可以用头部转动、对着镜子作画和kappa角引起的注视过冲来解释。此外,伦勃朗明显的斜视仅在其职业生涯早期的几年所画的那些画像中出现,而且伦勃朗及其学生为其他推测为非斜视的人所画的画像常常也会给人类似的斜视印象。
有几个因素可以解释为什么伦勃朗的一些自画像会让他看起来有斜视,而无需得出他实际患有斜视的结论。伦勃朗及其学生也可能将这种外观作为一种艺术风格来描绘。