An objective and efficient method for determining whether an individual is tired could provide an important tool in various fields, including biomedical influences, sleep disorder studies, industrial medicine and psychiatry. The purpose of this study is to assess pupillary oscillations, which are known to originate from activities of the autonomic nervous system. While the pupils are large and quiet in darkness when the subject is alert, they oscillate under the influence of tiredness. The pupil becomes smaller and begins to oscillate at higher amplitude and slower frequency (pupil constrictions +0.25Hz frequency); this fact was considered in connection with the physical fatigue wave reported in past reports.
Proper understanding of the optical system of the eye and the principles of clinical examination are important in evaluating visual functions and correcting refractive anomalies and/or vision loss. If we use equipment or methods without understanding which physical principles and procedures underly their use, we may introduce sizable errors into the outcomes of cataract and refractive surgeries. However, if we correctly understand how the technology and procedures interface with the optical system of the eye and the principle of optics, it is easy to enhance the accuracy and predictability not only of measurement, but also of surgical outcome. For more accurate correction, refractive and cataract surgeries should be based on proper understanding of optical properties of the eye. This paper reviews a number of problems associated with pre- and post-operative examinations in recent cataract and refractive surgeries; many approaches to overcoming these problems.
Function figures and orthonormal features of Zernike polynomials are described. Some of the polynomials are identical except for their angular direction, and they can be expressed with a linear combination of any two independent polynomials. We can accurately approximate even a complex wave aberration of ophthalmic optics, if some suitable principal components of the polynomials are chosen in advance. Ray aberration patterns corresponding to lower order Zernike polynomials are also described.
Adaptive optics (AO) ophthalmoscopes correct for monochromatic aberrations of the eye in real time, yielding high-resolution retinal images. In addition, AO scanning laser ophthalmoscopes (AO-SLO) have optical sectioning ability, yielding images at particular depth layers. Thus, images of specific retinal layers can be obtained. On the other hand, with the ophthalmoscope system called flood illumination, which involves illuminating an area of the retina and acquiring retinal images with an image sensor, it is difficult to observe a particular layer, since the reflective intensity of the photoreceptor layer is too strong to permit observation of other layers. With our AO flood illumination ophthalmoscope, which uses a Xe short-arc lamp with two different lighting methods, we obtained images of the nerve fiber layer and other layers of the retina.
Purpose: The light rays that induce glare perception during intraocular lens (IOL) use are classified into four types. We have developed a method of visualizing retinal images to investigate how these types of light rays affect glare perception.
Method: First, a fundus oculi irradiance table is calculated by ray-tracing simulation with an eye model and an IOL. A retinal image is then generated by mapping a picture of the environment on the fundus, while taking into account the irradiance table. A sharp-edged IOL is used in our simulation, with pupil diameter set at 8mm. Retinal images are generated for two scenes: outdoor-night and indoor-day. We also investigate the influence on glare of the four types of ray paths.
Results: Two types of ray paths (reflected and refracted rays from the lens edge) cause bright arcs around the central fossa, and have a relatively strong influence on glare perception.
Conclusions: We have developed a method for visualizing a retinal image based on a ray-tracing simulation. We generated retinal images and clarified the influence of the four types of rays on glare perception.