A Randomized, Repeated-measures Study to Measure the Temporal Frequency Response of Ocular Accommodation After Sustained Near Viewing.
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 20
- 试验地点
- 1
- 主要终点
- Gain and phase of ocular accommodation
研究概览
简要总结
In this experiment, subjects will view a cross pattern on the screen and be asked to focus their eyes on it. The cross pattern will look like it is moving towards and away from the eye in a back-and-forth motion. As the subjects focus their eyes on the shapes, the investigators will measure the focus of their eyes using a device called a wavefront sensor. This device uses infrared light to measure the optical properties of the eye in real time. Our goal is to find out how well the eye focuses before and after viewing images on a screen up close (25cm). Since many people spend a lot of time looking at a computer screen while at work or at school, it is important to understand how this affects the eye's ability to focus.
详细描述
In this experiment, subjects will view a Maltese cross pattern on a display through a Badal relay. Subjects will be instructed to accommodate to the pattern while a focus-adjustable lens optically moves the display closer and farther in depth as a sinusoidal function of time. As they do so, the investigators will measure the wavefronts of their eyes using a Shack-Hartmann wavefront sensor. The investigators will measure the gain and phase of the accommodative response of the subjects' eyes. Measurements will be made before and after sustained viewing of images on a computer screen 25cm away.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 35 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Between 18-35 years of age
- •Normal or corrected-to-normal (glasses/contact lenses) vision.
排除标准
- •Vision worse than 20/20 while wearing glasses / contact lenses.
- •Fragile or loose teeth (participants need to bite a piece of dental clay to stabilize their heads so that measurements can be taken from their eyes)
- •Current pregnancy (experiment requires sitting down without moving for stretches of time)
- •Heart disease
- •Personal/familial history of epilepsy
研究组 & 干预措施
Near viewing first first
In a given session of the experiment (1.5 hours), participants do 2 sets of accommodation tasks. One task happens after viewing a screen for 20 minutes at 25cm, and the other task happens after looking at a distant object (10m) for 20 minutes. There are two types of sessions: one in which the screen is viewed first ('near viewing first'), and the other in which the distant object is viewed first ('distant viewing first'). All participants do both sessions. However, in one arm, participants do the 'near viewing first' session first.
干预措施: Near viewing first (Other)
Near viewing first first
In a given session of the experiment (1.5 hours), participants do 2 sets of accommodation tasks. One task happens after viewing a screen for 20 minutes at 25cm, and the other task happens after looking at a distant object (10m) for 20 minutes. There are two types of sessions: one in which the screen is viewed first ('near viewing first'), and the other in which the distant object is viewed first ('distant viewing first'). All participants do both sessions. However, in one arm, participants do the 'near viewing first' session first.
干预措施: Distant viewing first (Other)
'Distant viewing first' first
In a given session of the experiment (1.5 hours), participants do 2 sets of accommodation tasks. One task happens after viewing a screen for 20 minutes at 25cm, and the other task happens after looking at a distant object (10m) for 20 minutes. There are two types of sessions: one in which the screen is viewed first ('near viewing first'), and the other in which the distant object is viewed first ('distant viewing first'). All participants do both sessions. However, in one arm, participants do the 'distant viewing first' session first.
干预措施: Near viewing first (Other)
'Distant viewing first' first
In a given session of the experiment (1.5 hours), participants do 2 sets of accommodation tasks. One task happens after viewing a screen for 20 minutes at 25cm, and the other task happens after looking at a distant object (10m) for 20 minutes. There are two types of sessions: one in which the screen is viewed first ('near viewing first'), and the other in which the distant object is viewed first ('distant viewing first'). All participants do both sessions. However, in one arm, participants do the 'distant viewing first' session first.
干预措施: Distant viewing first (Other)
结局指标
主要结局
Gain and phase of ocular accommodation
时间窗: Each measurement takes 10 seconds. In the experiment, we will take measurements over the course of approximately 1 hour.
Ocular accommodation is the focusing response of the lens in the eye. When the stimulus viewed by the participant changes in distance, the eye automatically refocuses. We measure this refocusing using a device called a wavefront sensor. We are particularly interested in the gain of accommodation, which is the ratio of the amplitude of accommodation to the amplitude of sinusoidal changes in stimulus distance. We are also interested in the phase of the accommodative response, which is related to the lag of the accommodative response.
Gain and phase of ocular accommodation
时间窗: Each measurement takes 10 seconds. In the experiment, the investigators will take measurements over the course of approximately 1 hour.
Ocular accommodation is the focusing response of the lens in the eye. When the stimulus viewed by the participant changes in distance, the eye automatically refocuses. The investigators measure this refocusing using a device called a wavefront sensor. The investigators are particularly interested in the gain of accommodation, which is the ratio of the amplitude of accommodation to the amplitude of sinusoidal changes in stimulus distance. The investigators are also interested in the phase of the accommodative response, which is related to the lag of the accommodative response.
次要结局
未报告次要终点
研究者
Benjamin Chin
Assistant Professor
Rochester Institute of Technology