• Korean Journal of Optics and Photonics
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• v.26 no.6
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• pp.299-305
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• 2015

Using Snell's Law without approximation, we analyzed focal points for parallel rays incident upon the cornea of a human eye. To calculate a ray's incident angle versus incident height for focusing on the same point, we used the ray reverse tracing method. We derived the theoretical conditions for an aspherical lens to remove the spherical aberration caused by a human eye. In this research, we held the rear surface of the lens to be spherical, for simple calculation, and calculated the lens curvature of the front surface to design an aspherical surface.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.2
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• pp.35-39
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• 2009

Purpose: In this study a program was developed to determine corneal aberrations using corneal shape of topographer and represented a wavefront and corneal aberrations using zernike polynomial. Methods: When the pupil size was 6 mm, we calculated new corneal shape data with zernike polynomials using corneal shape data of ORBSCAN topographer. We programmed the wavefront construction using ray tracing for corneal shape, then represented corneal aberrations having zernike polynomial with 6th order and 28 terms. Conclusions: We developed programs to determine a wavefront and corneal aberrations using corneal shape of ORBSCAN topographer. Theses results will be applied to a development of new topographer and prescription of contact lens and OK lens.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.1
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• pp.135-143
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• 2004

The Human body is subject to two patterns of senescence, both of which are represented in the eye and vision. This article discusses the anatomical and physiological changes in anterior and posterior segments which occur with age. The areas covered include the globe, lids, tears, conjunctiva, cornea, sclera, anterior chamber angle, iris, lens, choroid, vitreous and retina. A sample of 219 individuals between the ages of 50 and 79 years was tested with case history, slit lamp examination, palpebral fissure, horizontal visible iris diameter(HVID) and pupil size. The palpebral fissure decreases with age while HVID remains constant in all age classes. This study suggests that an understanding of anatomical and physiological changes which occur with age is helpful to all eye clinicians because the aging process affects all of the ocular tissues.