Beecher Mirage 4X and 5.5X

Beecher Mirage Binoculars are binocular telescopic systems designed  for use by individuals with low vision. They allow people with a visual impairment to view objects at a normal distance while using strong telescopic magnification, but with an exceptionally wide field of view. It uses Keplerian optics.  It is helpful for tasks such as viewing T.V, theatre, sporting events and in some cases bioptic driving. Our practice has prescribed over 1300 Beecher Mirage systems. The most common vision problem this has been prescribed for is conditions such as  macular degeneration and achromatopsia. A small portion of that total has been for bioptic driving.

The late Dr. William Beecher,world reknown ornithologist from the University of Chicago and Fields Museum and the late Fred Mitchell, developed the Beecher Mirage systems. Worn like eyewear, these 3.5-ounce binocular telescopic systems come in powers of 4X, 5.5X, 7X, or 8X. Only the 4.0X and 5.5X are approved for bioptic driving in Indiana. The 4X glasses have a 15-degree field of view with a viewing distance (focal range) of five feet to infinity; the 5.5X glasses have a 12- degree field of view with a viewing distance of six feet to infinity; the 7X glasses have a nine-degree field of view with a viewing distance of eight feet to infinity; and the 8X glasses have an eight-degree field of view with a viewing distance of 10 feet to infinity.

In Indiana we can use the 4.0X or 5.5X Beecher Mirage for bioptic driving.

 

 

Modifying the Beecher Mirage for Bioptic Driving

The Beecher Mirage 4X and 5.5X provide moderate magnification in a lightweight head borne binocular system. They work well for some bioptic drivers when combined over prescription eyeglasses. We learned early that when we combine the Beecher over Carrier eyewear, adding a slip-in sunglass adds an unneeded level of complexity and potential for the slip-in to shift. Thus, we prescribe two sets of carrier eyewear that the Beecher will sit over. One set of eyewear is a clear or minimally tinted eyewear for lower light levels. The other eyewear is a sunglass prescription. The Beecher can be used with either set of glasses as lighting determines..

We adapt the Beecher in several ways to fit over the eyewear frame.

 

 A low set bifocal of approximately 10 mm high is placed in the bottom to aid patients over 40. This allows them to see all the necessary gauges on the dashboard.

 

 

 

The Beecher can be mounted on the center nosepiece of the eyewear frame by removing the original moleskin covered pad and replace it with a smaller pad.  We must select a frame with a lower set bridge.  In some cases, we invert the nose pad upside down. In a few cases the Beecher can sit directly on the nose with the moleskin covered pad in from of the eyewear.  Each patient is different due to differences in the size of the nose.

 

The type of nose pad is changed and the Beecher is angled up slightly so that upon head tilt down the patient will view straight down the highway. The Behnke Modification can be added to improve the tilt up of the system. Behnke, a patient of our practice, used his experience as a physicist and researcher to design this helpful modification which we now fabricate for our patients.

 

 

Our experience fitting many patients with the Beecher system shows us that the Beecher 5.5X works very well for more visually impaired bioptic drivers especially those with age related macular degeneration. The fact that it is a binocular system seems to be helpful in many senior patients who appreciate the binocular vision.

 

 

 

To learn more about the the Behnke modification click here.

 

Beecher Demonstration

Here is a short video of a patient describing how they use the Beecher while driving.