Throwing hand and dominant eye seems to be a most reliable way for detecting functional asymmetry and cerebral laterality.
左或右利手和优势眼似乎是研究大脑功能不对称性和大脑偏侧型的最可靠的方法。
It means that you should use your dominant eye when peering through a telescope, camera viewfinder or keyhole - it will feel much more natural and easier to see that way.