New eyeglasses using high-power prisms988 views
New eyeglasses have been designed by researchers in which they have used high-power prisms to optimally enlarge the visual fields of patients with hemianopia — which is a state in which the visual fields of both eyes are cut by half. The innovative designs deal with a few limitations of on hand prism correction accessible to this populace.
Damaging either the left or right halves of the visual fields in both eyes, hemianopia is very frequently occurred by stroke, brain tumours, and head trauma. Hemianopia decreases the natural visual field of almost 180° to a simple 90°. People with hemianopia have complexity identifying vulnerabilities on their blind sides — directing to collisions, falls, and further accidents.
One method of dealing for hemianopia is to enlarge the visual field with prisms rising on or surrounded in eyeglasses.
A research team directed by Professor Eli Peli from Harvard Medical School has been growing prism devices to enlarge the visual field for these patients for above 15 years. The tangential prism glasses — their much latest commercially accessible device, launched in 2013 — have been illustrated to enlarge the visual fields of patients with hemianopia by in so far as 30°, optically shifting objects from the blind side of the visual field to the seeing side.
With the aim of enlarging the visual field on the blind side even further, the researchers discovered novel optical methods to make elevated power image shifting devices designed to curve the light beyond the 30° limit of conventional prisms.
By surrounding the present prism in a display lens that has prismatic power on the opposite side, the image shifting impact is elevated by the outline of the power of both prism kinds. This design — presented in the journal Optometry and Vision Science — permitted for more than 36° of development to the visual field on the patient’s blind side.
Peli further stated that “The new optical devices can improve the functionality of the current prism devices used for visual field expansion and may find use in various other field expansion applications such as a mobility aid for patients with tunnel vision,”