There are far fewer low-budget options in Montego Bay compared to nearby Negril, so this is mostly a mid-range area for the Caribbean, with a few really high-end places sprinkled in. The all-inclusive resorts in Montego Bay are excellent value, especially when packaged with a flight.
Instead of providing just two lens powers like bifocals (or three, like trifocals), progressive lenses are true multifocal lenses that provide a smooth, seamless progression of many lens powers for clear vision across the room, up close and at all distances in between.
It allows for fine adjustment of the focus. Because the objective lenses are parfocal, this knob is all that is required to bring a subject into focus when switching from one objective to another (All three objectives are designed to bring a subject into focus using the same working distance - lenses with the same working distance - length from slide to lens when the subject is in focus - are parfocal) .