A method to measure forward scattering in human eyes (straylight) was proposed more than 80 years ago, and the experimental results were presented, but a practical device has only recently appeared. TJ van den Berg has provided us with the basic and useful knowledge about the properties of straylight. To understand his papers clearly, further underlying knowledge is needed. Here, introductory knowledge for understanding scattering and the measurement technique for forward scattering are described.

Optical coherence tomography (OCT) angiography visualizes capillaries noninvasively. A certain part of the blood flow in the tissue can be depicted by detecting the time change of the OCT signal. Clinical devices equipped with OCT angiography have also appeared, and several clinical researches using OCT angiography have been actively conducted. This review outlines the history of development and characteristics of OCT angiography so far, and the current technical developments are briefly reported.

Evaluation of retinal blood flow is very useful for the clinical practice. Fluorescein angiography is still a gold standard to detect the abnormalities of the retina in patients with retinal vascular diseases, including diabetic retinopathy and retinal vein occlusion. In contrast to the angiography, a Laser Doppler velocimetry (LDV) and Laser speckle flowgraphy (LSFG) have been used to measure retinal blood flow in clinical researches. However, there were some problems with these techniques. Recently, the Doppler-OCT has been developed as a novel technique to measure retinal blood flow non-invasively. Herein, I have summarized the principal of the measurement of retinal blood flow using a Doppler-OCT.

In addition to standard optical coherence tomography (OCT) intensity images, polarization-sensitive OCT (PS-OCT) can visualize birefringence of fibrous tissues and polarization scrambling of melanin pigment, thereby adding new image contrasts. In this paper, an overview of the PS-OCT technology is described briefly. It is shown that polarization is a fundamentally important concept for OCT, can cause an artifact in standard OCT, and can add image contrasts that cannot be seen in standard OCT. PS-OCT images of scarred filtering bleb created by trabeculectomy are shown as a representative clinical example.

In this review, I present a brief discussion about clinical application of polarization sensitive optical coherence tomography and a polarization sensitive scanning laser ophthalmoscope for macular diseases. Multimodal imaging with these polarimetry techniques has the potential to completely change macular disease clinics.

Measurements to quantify eye fatigue with both-eye open conditi on are not well investigated, Eighteen subjects were instructed to play a commercial 3D game with a portable ga me console for 30 minutes as visual load and changes of accommodation and vergence responses between pre-load and po st-load were examined by a custom-built binocular wavefront sensor. In our measurements, a fixation target were driven reciprocally with constant-diopter (＋/－0.25D/sec.) or with a stepwis e (2.0/0.2D) stimuli. The late ncies of convergence and divergence after visual-load were significantly prolonged (P＜0.05) in the stimuli for reciprocal movements. Similarly, it was found in stepwise stimulus the time required to change the accommodation from 80％ to 10％ i n relaxation phase became longer (P＜0.05) in post-load measurement. Our results suggest the accommodation an d vergence responses measured by a binocular wavefront sensor can be applied to objective evaluation of eye fatigue. Particularly, the convergence, which is less affected by age, is promising for application to the over middle-aged people.

In the original version of the hexagon dot stereo test, the par ticipant gives the sign of apparent depth of a central dot with respect to surrounding dots. The present study examined a modified version of the stereo test where two sets of hexagon dots are arranged side by side to measure not the accur acy but the precision of stereopsis. A comparison of the stereo thresholds, precision and accuracy for 30 observers validates the modification to the test. In addition, the results obtained in the present s tudy using a liquid-crystal-display monitor and the anaglyph method were compared with results obtained in a previous study using two oscilloscop es and polarized filters. Pre sumably owing to crosstalk, the stereo acuity determined by t he anaglyph method tended to be lower. However, the results were good enough to demonstrate the efficiency of the anaglyph method for a quick stereo screening test.