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

视觉涉及一系列复杂的过程，使我们能够从物质世界中提取信息。当你阅读这篇文章时，文本的图像是由你眼睛的光学元素形成的，这个图像是由你视网膜上的光敏细胞感知的。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含义。这发生在你的眼睛跳跃般的运动之间的几分之一秒内，这些运动将你的视线转移到文本上。即使在我们认为我们的眼睛是静止的时候，它们也会不断地进行微小的运动，这是看到任何东西的基础。感觉输入的中断，如视网膜退化或屈光不正，对视觉系统可获得的信息造成了基本限制。视力障碍对个人的健康、幸福和生活质量有重大影响。儿童时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，以及眼睛的有效运动的改变。解决视觉障碍最好的方法是跨学科，跨越这些层面。自适应光学是一种最初为天文学开发的强大技术，它彻底改变了眼睛的研究，使人类的视觉具有非凡的精确度。通过校正每只眼睛中存在的光学失真，自适应光学允许对活着的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睛运动。通过控制眼睛的光学变形，自适应光学还可以研究屈光不正对视力的影响。我将采取跨学科的方法，结合人类视觉的精确实验，开发自适应光学技术，以了解视觉系统如何处理信息，以及视觉障碍是如何破坏这一过程的。我将通过有针对性地调查导致视力受损的两个主要原因来解决这些基本问题：1.老年性黄斑变性在英国影响着大约60万人，通过导致中央视力丧失而严重影响视力-想象一下，无论你看哪里，盲点都跟随着你是多么的困难。由于无法治愈，治疗的目的是保护剩余的视力，因此早期发现至关重要。我将研究视网膜退化、眼球运动和视觉功能之间的关系。这将为辅助视力和眼动训练等干预措施提供信息，以最大限度地利用患者剩余的视力。自适应光学的高精度将使我能够非常敏感地测量眼球运动的变化。我将寻找可以筛查的特征变化，从而很早就发现疾病。在英国，屈光不正(如近视和散光)影响着大约七分之一的儿童。即使是健康的眼睛，也有更复杂的高阶光学失真，这是眼镜无法纠正的。视觉扭曲会损害视觉敏锐度，例如辨认图表上字母的能力，但在阅读等对认知要求更高的任务中，可能会导致进一步的问题。我们的社会大量使用文本来传达重要的信息。我的研究将使用自适应光学来研究光学失真对阅读的影响，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设备或眼睛指导培训，或通过为教育材料设计更耐屈光误差的字体，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.