The magnification offered by Galilean systems usually ranges between 1.8x and approx. 2.7x. The field of view is still relatively large at these magnifications, while the risk of blurry images during use is relatively low. The majority of Galilean systems cannot be variably focused. They are used either for viewing at infinity or, for closer distances, by adjusting the objective or by mounting front caps.
Thanks to their design, Galilean systems are small, lightweight optical systems.
Their handling is quite easy, which makes them particularly suitable for older people.
How are telescopic spectacles converted for near vision?
Frame-mounted Galilean telescopic systems impress with sharp, brilliant images. By mounting a front cap lens (= magnifier), the telescopic systems can be used for near vision (e.g. reading).
Unlike high addition spectacles, telescopic spectacles with front cap lenses can be used at significantly greater working distances. With these front caps, it is possible to achieve magnifications up to 8.1x at a working distance of 83 mm. Galilean systems offer many advantages for visually impaired people:
Flip-up front caps for easy use at near distances (monocular)
Older visually impaired people often also lack the necessary fine motor skills. To make the use of telescopic spectacles easier for these patients, it is possible to combine a basic front cap lens with an add-on front cap lens that can be flipped up and down.
By combining the two front cap lenses, the system can be used at two distances. With the basic front cap lens, the system can be used at an intermediate working distance (2 m, 1.52 m or 1 m) , e.g. for watching TV (no need for a corrective lens).
To adjust the system for near vision, a second hinged front cap lens is folded down in front of the system; a slight touch of the finger is all it takes to flip the add-on front cap lens up or down thanks to the robust spring hinge. The handling is very easy for visually impaired people, enabling them to change quickly between near and distance vision.
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Further information on product solutions for visually impaired people is provided at www.improvision-lvs.com.