This study looks at different machines used to check how well people can see. These machines are called perimeters. The study compares three perimeters: TEMPO, VisuALL, and HFA. Each person in the study will have their eyesight tested only once. During the test, doctors will check different things about your eyes, like how well you see in different parts of your field of vision. Tests include MD (mean deviation), PSD (pattern standard deviation), FT (fixation target), VFI (visual field index), and OCT (optical coherence tomography). You will also answer some questions about your vision.

• You need to have good eyesight, at least 20/30 vision or better, to join.
• Only one visit is needed for the study.
• If you have certain eye problems, like severe glaucoma, you cannot join.