Refractive Dilemma
نویسندگان
چکیده
A 21-year–old man was re ferred to an ophthalmology clinic insisting on getting rid of his glasses which he had been using for 11 years. Gross ocular examination was normal except for small eyes. Best corrected visual acuity (BCVA) was 20/40 and 20/50 with +16.00 and +18.00 diopter (D) glasses in his right and left eyes respectively. No ocular deviation was observed and slit lamp and fundus examinations were within normal limits. Figures 1, 2 and 3 demonstrate his A-scan ultrasound biometry and ocular topographic features.
منابع مشابه
Refractive Surgery Dilemma
A 33-year-old man seeking refractive surgery presented with refractive error of -1.75 -4.0×20° in the right and -0.75 -2.5×170° in his left eye in January 2009; best spectacle-corrected visual acuity (BSCVA) was 20/25+ and 20/20respectively. All ocular examinations were unremarkable and family history for keratoconus was negative. He had previously obtained consultation for refractive surgery i...
متن کاملSmall refractive errors--their correction and practical importance.
Small refractive errors present a group of specifc far-sighted refractive dispositions that are compensated by enhanced accommodative exertion and aren't exhibited by loss of the visual acuity. This paper should answer a few questions about their correction, flowing from theoretical presumptions and expectations of this dilemma. The main goal of this research was to (dis)confirm the hypothesis ...
متن کاملOn diffraction within a dielectric medium as an example of the Minkowski formulation of optical momentum.
The Abraham-Minkowski dilemma relates to the disputed value of the optical momentum within a dielectric medium and whether the free-space value should be divided (Abraham) or multiplied (Minkowski) by the refractive index. Although undoubtedly simplistic, these two approaches provide intuitive insight to many subtle problems in optical physics. This paper reviews a modified version of the Einst...
متن کاملReal and Pseudoaccommodation in Accommodative Lenses
In the attempt to manage presbyopia, different intraocular lens designs have been proposed such as monofocal IOLs with monovision or multifocal IOLs. Even though the lenses mentioned offer satisfactory visual results, contemporary ophthalmology has not completely answered the presbyopic dilemma by simulating the accommodative properties of the crystalline lens itself. Accommodative IOLs were de...
متن کاملStudying Focusing Properties of Graded Index Photonic Crystals Made of Material with Different Refractive Index
In this paper we investigate focusing properties of graded index (GRIN) photonic crystal (PC) structures which are composed of different materials with different refractive indices. GRIN PC structure is constructed from air holes in dielectric background. The holes radii are varied in the normal direction to the propagation in such a way that a parabolic effective refractive index is produced. ...
متن کامل