Abstract: An arrangement for determining the location relative to eyeglass frames of points at which visual axes penetrate through eyeglass areas of eyeglasses includes a sighting object having two concentric target zones one of which emits polarized light. A support is removably attached to an eyeglass frame and at least one polarized filter having a polarization plane extending transversely of that of the light issuing from the one target zone is mounted on the support for movement in parallelism with the respective eyeglass area toward a position of registry with the respective visual axis, in which position the polarized filter at least substantially obscures the one target zone. Another, larger, polarization filter is removably mounted on the support and obscures the one target zone for the eye which is not then being examined.