4 resultados para Multifocal intraocular lens

em Bucknell University Digital Commons - Pensilvania - USA


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Eye injuries are a large societal problem in both the military and civilian sectors. Eye injury rates are increasing in recent military conflicts, and there are over 1.9 million eye injuries in the United States civilian sector annually. In order to develop a better understanding of eye injury risk, several previous studies have developed eye injury criteria based on projectile characteristics. While these injury criteria have been used to estimate eye injury potential of impact scenarios, they require that the mass, size and velocity of the projectile are known. It is desirable to develop a method to assess the severity of an eye impact in environments where it would be difficult or impossible to determine these projectile characteristics. The current study presents a measurement technique for monitoring intraocular pressure of the eye under impactloading. Through experimental tests with a custom pressure chamber, a subminiature pressure transducer was validated to be thermally stable and suitable for testing in an impact environment.Once validated, the transducer was utilized intraocularly, inserted through the optic nerve, to measure the pressure of the eye during blunt-projectile impacts. A total of 150 impact tests were performed using projectiles ranging from 3.2 mm to 17.5 mm in diameter. Investigation of the relationship between projectile energy and intraocular pressure lead to the identification of at least two distinct trends. Intraocular pressure and normalized energy measurements indicated a different response for penetrating-type globe rupture injuries with smaller diameter (d < 1 cm)projectiles, and blunt-type globe rupture injuries with larger diameter (d > 1 cm) projectiles. Furthermore, regression analysis indicates that relationships exist between intraocular pressureand projectile energy that may allow quantification of eye injury risk based on pressure data, and also that intraocular pressure measurements of impact may lead to a better understanding of thetransition between penetrating and blunt globe rupture injury mechanisms.

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In my thesis, I explore the cultural history of the French Revolution and its relation to the modern era which ensued. Many historians have studied the French Revolution as it relates to culture, the rise of modernity, and fashion. I combine the unique histories of all three of these aspects to reach an understanding of the history of the French Revolution and fashion’s role in bringing about change. In the majority of literature of costume history, discussion of fashion surrounds its reflective properties. Many historians conclude fashion as a reflection of the broader cultural shifts that occurred during the Revolution. I, on the other hand, propose that fashion is an active force in bringing out cultural change during this time. In exploring fashion as a historical motivator, I examine the aesthetic world of fashion from 1740 to 1815, the modern system of cultural dissemination of fashion through particular historical heroes, and the rise of “taste” and its relation to modern identity. Through aesthetics, culture, and identity, I argue that fashion is a decisive force of culture in that it creates a visual world through which ideas form and communicate.

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This thesis provides a critique of Western media articles concerning self-immolation in Tibet. I begin by illustrating how the Western media provides reductionist accounts of Tibetan self-immolation by depicting the act solely as a form of political protest in response to Chinese occupation. I argue that these limited portrayals of self-immolation can be attributed to the Shangri-La imagery that characterizes much of the Western conceptions of Tibet. Through Shangri-La imagery, both Tibetans and their Buddhist religion are portrayed as utopic, peaceful, and able to provide the antidote to solving Western problems relating to modernization and consumerism. After illustrating the ways in which Shangri-La imagery influences Western media portrayals of Tibetan self-immolation, this thesis explores the commonly disregarded Buddhist dimensions of the act. Looking to Buddhist doctrine, scripture, and history, this thesis establishes a clear relationship between self-immolation and Buddhism, which situates the act as being more complicated than mere political protest. I argue that these limited portrayals given by the Western media are problematic because they overlook a fundamental aspect of self-immolation, thus potentially misrepresenting Tibetans. This thesis explores the Buddhist dimensions of self-immolation as a possible way to further understand what has led more than one hundred Tibetans to perform this act during the time of political crisis.