An optical measuring apparatus includes a first light source, a second light source and a switching unit. The first light source is used to emit a first light toward a first direction. The second light source is used to emit a second light toward a second direction. The switching unit selectively switches to a first mode or a second mode. When the switching unit switches to the first mode, it blocks the second light and let the first light emitted to an aiming region on eyeball to perform an optical aiming and determine an eye axis center position on the eyeball; when the switching unit switches to the second mode, the switching unit changes the second light from the second direction to the first direction to let the second light emitted to the eye axis center position on the eyeball to perform an optical measurement.