Bioptics are telescopic eyeglasses specially designed for low vision among the visually impaired. These tiny telescopes are mounted toward the top of the eyeglass lens. The bioptic lenses are mounted through spectacle lenses to enable the telescope to be brought into view when one tilts the head. They improve vision by allowing an individual to see clearer images and further away.
Bioptics are best suited for individuals whose vision in the better eye is 20/300 or whose vision is lost due to macular degeneration or other ocular diseases that lead to central vision loss. Bioptic telescopes may also benefit the classroom student who needs both far vision for the chalkboard and near vision to view his/her book. The patient can enjoy the outdoor scenery, TV shows, a baseball game, the opera, movies, and be able to see people’s faces.
Because bioptics are mounted on telescopes, the patient uses it hands-free. It also provides quick and easy access by tipping the head. The patient only needs to drop their head slightly so that the telescope can be aligned with their eyes. It can be both monocular and binocular, depending on the purpose. While some patients will require two telescopes, others need only one, which is mounted over the eye with a better vision.
Bioptics are prescribed by either ophthalmologists or optometrists who specialize in low vision. These lenses are found in different sizes, powers, and styles. Patients who use bioptic telescopes can still maintain mobility as well as benefit from a telescopic system. Because the telescope is mounted high in the lens, it doesn't interfere with the patient's movements, although it's ever available for distance viewing.
Also Known As
- Bioptic lenses
- Bioptic telescopes
- Bioptic lens system
Telescopes come in various powers of magnification. While some have a wider field of view, others are lighter and smaller. Types of bioptics include the Standard Bioptic Telescopes such as the various subtypes of Model 1 and II, manufactured from glass lenses mounted in a plastic housing. Others include the Full Diameter Telescopes and the Wide Angle Bioptic Telescopes (with a larger visual field). Most of these types are built with round objective lenses, while a few others have rectangular objective lenses.
Individuals who come short of the standard legal visual acuity can use bioptic lenses to drive automobiles comfortably since bioptics improve a driver’s far vision.
Bioptic lenses are designed for both magnification of objects and distance vision. Those who have lost mild to moderate central vision but with an intact peripheral (side) vision are permitted to drive in the US if they are using a bioptic lens system. The driver using bioptic lenses looks through the main eyeglass lenses about 90-95% of the time they are driving. To see color, road activity, or detail, the driver briefly dips down the telescopic lens unit and occasionally uses a simple synchronized head and eye vertical drop technique.
However, to be effective on the road, the driver will need training on the requisite critical skills for bioptic driving. When the driver wants magnification, s/he will glance through the binocular part and view details such as street signs, traffic lights, and far away objects. Most of the time, the driver will look through their normal eyeglass lenses and only briefly sight through their telescopes. For instance, a driver using an x4 telescope can see a road sign at 80 feet through the bioptics. Had they been using their normal vision, that same road sign would be sighted at 20 feet.
Bioptic lenses can also be used by age-related macular degeneration (AMD) patients.
AMD is the main contributor to legal blindness in the West in people aged 55 and above. AMD patients cannot see small details like a letter's or face's contour since they lose their central vision, although the peripheral vision stays intact. Patients with other degenerative eye diseases can also benefit from bioptics. Bioptic lenses designed for AMD have autonomous visual pathways that permit switching between regular and magnified vision. Studies on a built-in zoom to assist patients with AMD are ongoing.
Patients can achieve closer working distances to accomplish tasks like reading.
To enable reading at closer distances, a reading cap is applied over the telescope's front end. Whether near or intermediate, any desired working distance can be achieved when the reading cap focuses the telescope, based on the power of the telescope.
A team of researchers have also explored combining tinted contact lenses with bioptic lenses for patients with albinism.
Albinism is a condition marked by a decrease or absence of melanin, which may lead to abnormalities in the development of the eye and visual pathways. When albinism patients use tinted contact lenses, they depend less on telescopes when driving in addition to decreased glare leading to greater visual comfort. The combination also provides patients with better visual acuity than if they had only used telescopes.
Disadvantages of Bioptic Lenses
- The undesirable cosmetic appearance which interferes with social interaction. Bioptics don’t look like normal prescription glasses because the telescope is mounted just above the eye.
- Those worn on the head result in a narrow field of view which requires the patient to turn his or her head directly towards the target view.