A window to the mind: Developing adaptive optics to understand changes in visual behaviour with eye disorders

观看涉及一系列复杂的过程，使我们能够从物理世界中提取信息。当你阅读时，你眼睛的光学元件形成了文本的图像，这个图像被视网膜上的感光细胞感知到。视网膜和大脑中的神经元处理这些感官输入，最终让你从文本中提取意义。这发生在你的眼睛跳跃般的运动之间的几分之一秒内，你的目光在文本上移动。即使在我们认为我们的眼睛是静止的时期，它们也会不断地进行微观运动，这是看到任何东西的基础。感觉输入的中断，例如视网膜变性或屈光不正，对视觉系统可用的信息造成了根本性的限制。视觉障碍严重影响个人的健康，福祉和生活质量。儿童期的视力障碍会影响学习成绩，老年人的视力障碍会严重限制日常活动并影响独立性。视觉障碍在许多层面上都有影响，从眼睛的变化到视觉和认知处理的缺陷，以及眼睛有效运动的改变。视觉障碍最好通过跨学科的方法来解决，在这些层面上工作。自适应光学是一种强大的技术，最初是为天文学开发的，它彻底改变了眼睛的研究，使人类的视觉特征具有非凡的精度。通过校正存在于每只眼睛中的光学失真，自适应光学允许对活体人眼中的单个细胞进行成像，并提供令人兴奋的新功能，以前所未有的精度跟踪最微小的眼球运动。通过操纵眼睛的光学畸变，自适应光学还允许调查屈光不正对视力的影响。我将采取跨学科的方法，开发自适应光学技术，结合人类视觉的精确实验，以了解视觉系统如何处理信息以及视觉障碍如何破坏视觉系统。我将通过有针对性地调查视力障碍的两个主要原因来解决这些基本问题：1。视网膜相关性黄斑变性影响着英国约60万人，通过导致中心视力丧失严重影响视力-想象一下，无论你看哪里，盲点都会随之而来。由于无法治愈，治疗的目的是保留剩余的视力，因此早期发现至关重要。我将研究视网膜变性、眼球运动和视觉功能之间的关系。这将为视觉辅助和眼动训练等干预措施提供信息，以充分利用患者剩余的视力。自适应光学的高精度将使我能够对眼球运动的变化进行非常敏感的测量。我将寻找可以筛查的特征性变化，从而导致疾病的早期发现。屈光不正（例如近视和散光）影响英国约七分之一的儿童。即使在健康的眼睛中，也有更复杂的高阶光学畸变，这些畸变是眼镜无法矫正的。光学畸变会损害视觉敏锐度--比如识别图表上字母的能力--但在更高认知要求的任务中会导致进一步的问题，比如阅读。我们的社会大量使用文本来传达重要信息。我的研究将使用自适应光学来研究光学畸变如何影响阅读，例如通过损害识别或扰乱眼球运动。这将通过改进视觉辅助工具或眼睛指导培训，或通过设计对屈光不正更稳健的教育材料字体，使信息更容易获得。

Seeing involves a complex set of processes that allow us to extract information from the physical world. As you read this, an image of the text is formed by the optical elements of your eye and this image is sensed by the light-sensitive cells that tile your retina. Neurons in your retina and brain process this sensory input, ultimately allowing you to extract meaning from the text. This happens in a fraction of second between jump-like movements of your eyes that shift your gaze across the text. Even during the periods when we think our eyes are still, they continually make microscopic movements that are fundamental to seeing anything at all. Disruption to the sensory input, such as by retinal degeneration or refractive errors, places a fundamental limit on the information available to the visual system. Visual disorders significantly impact on an individual's health, wellbeing and quality of life. Visual impairments in childhood can affect school performance, and in the elderly they can severely restrict everyday activities and affect independence. Visual disorders have their effect at many levels, from changes in the eye, to deficits in visual and cognitive processing, and alterations to the efficient movement of the eyes. Visual disorders are best tackled with a cross-disciplinary approach, working across these levels.Adaptive optics is a powerful technique originally developed for astronomy that has revolutionised the study of the eye, allowing human vision to be characterised with extraordinary precision. By correcting for optical distortions, which are present in every eye, adaptive optics allows imaging of individual cells in the living human eye and provides exciting new capabilities for tracking the tiniest of eye movements with unprecedented accuracy. By manipulating the optical distortions of the eye, adaptive optics also allows investigation of the impact of refractive errors on sight. I will take an interdisciplinary approach, developing adaptive optics techniques in combination with precise experiments in human vision to understand how the visual system processes information and how this is disrupted by visual impairments. I will address these fundamental questions through targeted investigation of two leading causes of visual impairment: 1. Age-related macular degeneration affects around 600,000 people in the UK, severely affecting sight by causing loss of central vision - imagine the difficulty of having a blind spot follow wherever you look. Being incurable, treatments aim to preserve remaining sight and so early detection is crucial. I will investigate the relationship between degeneration in the retina, eye movements and visual function. This will inform interventions, such as visual aids and eye movement training, to make the best use of patients' remaining sight. The high precision of adaptive optics will allow me to make very sensitive measures of alterations to eye movements. I will look for characteristic changes that could be screened for, leading to very early detection of disease.2. Refractive errors (e.g. myopia and astigmatism) affect around 1 in 7 children in the UK. Even in the healthy eye, there are more complex high-order optical distortions that are not correctable with spectacles. Optical distortions impair visual acuity - such as the ability to identify letters on a chart - but can cause further problems in more cognitively demanding tasks, such as reading. Our society makes heavy use of text to convey important information. My research will use adaptive optics to investigate how optical distortions impact on reading, for example by impairing recognition or disrupting eye movements. This will enable better accessibility to information, through improved visual aids or eye guidance training, or through designing fonts for educational materials that are more robust to refractive errors.