Toyota has extended warranty for certain models for this same problem, but not for Prius. My car has 117,000 miles and this problem has been going on for at least the last 25,000 miles (based upon orange warning triangle). According to dealer, problem is with rings (which is the recall for other Toyota cars). Also, according to dealer, this is a real problem for other Prius owners with 100,000+ miles.
Concave lenses in glasses correct this shortfall by spreading out the light before it reaches the eye, thereby enabling the person using them to see distant objects more clearly. Cameras. Camera manufacturers use combinations of concave and convex lenses to improve the quality of photographs.
Nikkor 28-200 mm zoom lens, extended to 200 mm at left and collapsed to 28 mm focal length at right. A zoom lens is a mechanical assembly of lens elements for which the focal length (and thus angle of view) can be varied, as opposed to a fixed focal length (FFL) lens (see prime lens). A true zoom lens, also called a parfocal lens, is one that maintains focus when its focal length changes. A lens that loses focus during zooming is more properly called a varifocal lens. Despite being marketed as zoom lenses, virtually all consumer lenses with variable focal lengths use varifocal design.