The Effects of Protective Eyewear on Glare and Crystalline Lens Transparency

Sakamoto, Y.; Sasaki, Kohsuke; Kojima, Masami; Sekiya, Hiroshi; Sakamoto, Akiko; Sakai, Masumi; Tatami, Akiyo

doi:10.1159/000060813

Cited by 5 publications

(4 citation statements)

References 4 publications

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“…Traditional sunglass designs decrease front‐on light exposure but there is evidence that some are ineffective in eliminating the nasal concentration of obliquely incident light (Narayanan et al. , 1996; Sakamoto et al. , 1999, 2002; Kwok et al.…”

Section: Sun Protectionmentioning

confidence: 99%

Peripheral light focusing as a potential mechanism for phakic dysphotopsia and lens phototoxicity

Kwok¹,

Daszynski²,

Кузнецов³

et al. 2004

Ophthalmic Physiologic Optic

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Our aim was to examine secondary image formation in the anterior segment caused by peripheral light focusing (PLF) in the human cornea, and in particular the crystalline lens. Non-sequential ray-tracing (OptiCAD) was applied to an anatomically based human eye model, which incorporates a gradient index crystalline lens. For analysis of the limbal effect, we varied the incident angle from 100 to 122 degrees, while for the crystalline lens effect, the incident angle was varied from 60 to 90 degrees. The corneal shapes studied included central radii from 7.4 to 8.2 mm with a range of shape factors. In each case, we computed the peak and average intensities, and the area of exposure at the limbus or lens periphery. The computation was repeated with a previous model eye for comparison. For the limbal effect, a peak intensity gain of x22.5 was found at an incident angle of 104 degrees which compares well with previous results. The average intensity gain at this angle was x7.5 over an area of 0.23 mm2. Steeper corneal curvature produced a greater PLF effect. For the crystalline lens effect, maximum UVA (365 nm) intensity gain peaked at x8.6 at 84 degrees with average intensity gain of x2.3. The area of UVA exposure peaked at 4.7 mm2 at 70 degrees. A relatively wide range (30 degrees ) of incident angles produced peak PLF gains of x3 or more in the lens. Significant focusing of light is directed to the nasal limbus, and to a lesser extent to the crystalline lens over a broad range of incident angles. PLF in the nasal cornea is reduced by an order of magnitude when a UV-blocking soft contact lens is used. The concentration levels and intraocular sites of PLF action on UV and visible light suggest a new mechanism of phakic dysphotopsia and lens phototoxicity.

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Section: Sun Protectionmentioning

confidence: 99%

Peripheral light focusing as a potential mechanism for phakic dysphotopsia and lens phototoxicity

Kwok¹,

Daszynski²,

Кузнецов³

et al. 2004

Ophthalmic Physiologic Optic

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“…Dysphotopsia in phakic patients may improve with correction of the refractive error [8], special lenses [9], sunglasses [10], lenses with filters [11] and other techniques. In patients with significant cataracts, surgery is the option [6].…”

Section: Pseudophakic Dysphotopsiamentioning

confidence: 99%

Pseudophakic Dysphotopsia

Aguilar¹

2020

Intraocular Lens

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Pseudophakic dysphotopsia is an unwanted entoptic phenomenon caused by intraocular lenses. Dysphotopsias have been classified as positive (brightness, streaks, haze, or glare) and negative (temporal arc or half-moon crescent) in the visual field. These visual phenomena seem to be well tolerated cause in the case of positive dysphotopsia, but not as well in the negative cases that sometimes discomfort to the patient. The incidence of dysphotopsia ranges from 20% to 77.7%, and the prevalence seems not to be altered by the type of intraocular lens. Pseudophakic dysphotopsia continues to be enigmatic over time; however, many efforts are being made in order to resolve the mystery. In this chapter, the evolution of the dysphotopsia, possible causes, and proposed treatments will be described.

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“…The visual function during recovery and return to the initial state (adaption to low levels of luminance after contact with eyes) decreases (Stringham, 2011 ;West , 2002;Hassan, 2002). The visual function and recovery time associated with glare are affected by environmental parameters (restricting lighting conditions and the placement of light source), individual parameters (vision health, glaucoma, corneal edema, macular edema, and age i.e., with increasing age an increase occurs in opacities and opacity of media, and consequently rises the scatter of light and glare), and parameters of glare (the brightness level that is directly related to glare, the angle of glare source, the size of glare source which is usually 0.3 or 0.6 degrees, and duration of exposure) (Hammond, 2013;Vos, 2003;Stringham, 2008;Sakamoto, 2002;Mahjoob, 2016;Sewall, 2016). The measurement of first type of glare is made by setting peripheral luminance conditions, and the seeing through the devices such as Miller-Nadler Glare Tester and Brightness Acuity Test.…”

Section: Introductionmentioning

confidence: 99%

Use of Functional Balance Measurement Tools to Predict the Fear of Falling in Faller and Non-Faller Chronic Stroke Patients

et al. 2018

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Background and Objective: Glare can affect vision in normal and abnormal individuals. It seems that threshold and normal values of glare have been less mentioned in various sources. The aim of this study was to determine acuity preserve in glare situation in normal subjects. Methods: 48 subjects (96 eyes) aged 18 to 25 years with normal visual acuity, and without any refractive error participated in this study. The acuity preserve in glare situation was measured at different light intensity conditions with Metro vision glare test at different luminance and visual field. Results: Glare source in each luminance at the nasal side may show better acuity preserve in glare situation. The maximum score for nasal and temporal source for 1 cd/ m 2 condition was 57.398 and 51.282 respectively. The same situation was seen for 5 cd/m 2 (P<0.001). However, in glare for luminance background of 1 cd/m 2 , and 5 cd/m 2 were significantly different (P<0.001). The acuity preserve in glare situation for 5 cd/ m 2 background was higher than 1 cd/m2 luminance in both temporal and nasal sides. Conclusion: Acuity preserve in glare situation in luminance of 5cd/m2 in both temporal and nasal was more than1 cd/m 2. Acuity preserve in nasal glare situation was more than temporal glare situation.

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The Effects of Protective Eyewear on Glare and Crystalline Lens Transparency

Abstract: Sunglasses not only protect against glare but also stabilize visual quality under various light conditions (e.g. passing through a tunnel while driving). Aging changes in lens transparency should be specially considered when developing protective eyewear.

Cited by 5 publications

References 4 publications

Peripheral light focusing as a potential mechanism for phakic dysphotopsia and lens phototoxicity

Peripheral light focusing as a potential mechanism for phakic dysphotopsia and lens phototoxicity

Pseudophakic Dysphotopsia

Use of Functional Balance Measurement Tools to Predict the Fear of Falling in Faller and Non-Faller Chronic Stroke Patients

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