Aids for Tunnel Vision
The Ocutech Image Minifier (IM) intended for use by patients with restricted visual fields (tunnel fields) from Retinitis Pigmentosa (RP), Glaucoma, and other visual disorders, to enhance peripheral field awareness. It is used by holding it close to the eye, or when attached to eyeglasses.
The Ocutech Field Viewer (FV) is held at arm’s length and used as an aid in mobility and in other visual activities. It functions by reducing the image size, in effect, placing more visual information into the visual field.
The Ocutech InstaMount Field Expander (FE) is a smaller and lighter version of the Image Minifier that is designed to be attached to eyeglasses using one of several different prescribing options.
Ocutech Image Minifier
The Ocutech Image Minifier is intended for use by patients with restricted visual fields (tunnel fields) from Retinitis Pigmentosa (RP), Glaucoma, and other visual disorders, to enhance peripheral field awareness. It achieves this effect by reducing the image size, so that in effect, more is seen in the same amount of space.
The 50% image size reduction produced by IM is optimal because it reduces the image size enough to enhance peripheral visual field awareness, but not so much as to reduce visual acuity through the aid or to produce bothersome barrel distortion. As compared to reversed Galilean Telescopes, the IM is specifically designed as an image minifying device, providing a flat field, with a wide ocular lens to allow for scanning through the device.
The Ocutech IM can be used in a trial frame for demonstration purposes, handheld with a neck strap, or spectacle mounted for either monocular or binocular use.
- Crisp, undistorted, flat field
- Wide ocular lens permits scanning through the device
- 50% field enhancement effect with minimal acuity loss
- Prescribe as either spectacle mounted, or handheld with neck strap
- Trial-ring version available for demonstration
- No eye piece correction required
- Adjustable focus allows optimum focus for each patient
- Huge depth of field
- Monocular or binocular applications
Visit our video gallery for presentation about the Ocutech Image Minifier.
The Ocutech IM can be demonstrated either in a trial frame or handheld. The patient should be positioned facing a door frame (or other appropriate obstacle) close enough that he/she is unable to see both sides of the door jam. Without moving the patient, place the IM in position in front of the patient’s dominant eye (the preferred sighting eye) and allow them to notice that now both sides of the doorway are now visible, (or that they require less head or eye turn) and they will be able to pass through more safely. Once this concept has been demonstrated and appreciated, allow the individual to walk while using the aid either in the trial frame or handheld.
The design of the IM chassis allows for a fine focus of the device my simply loosening the set screw and sliding the front and back of the IM in and out until the image is clearest for the user. Usually only a very slight adjustment is required.
Don’t forget to re-tighten the set screw once the best focus is achieved. Focusing for different distances is not required due to the large depth of field of the device. The IM can be prescribed for handheld use (with a neck strap) or spectacle mounted in either a monocular or binocular design. When spectacle mounted they can be ordered in the center of the lens (full-diameter) or in a top position (bioptic) mounting.
To the non-visual field restricted individual who looks though the IM, a narrow field of view will be experienced. This is because the overall field of view through the aid, while minified, is narrower than that of the normally sighted individual. To experience the benefit of the IM to the individual with tunnel visual fields, place a pinhole occluder in a trial frame and note the very narrow field of view. Now place the IM in front of the pinhole occluder and notice how much more field of view becomes visible.
The Ocutech Field Viewer (.25x FV)
The Ocutech Field Viewer (FV) is a 48mm diameter bi-concave lens mounted in a plastic ring. The FV is intended to be used by the visual field restricted patient as an aid in mobility and in other visual activities. It functions by reducing the image size, in effect, placing more visual information into the visual field. It is intended to be held at arm’s length, at which point the field viewer reduces image size by approximately 4 times. Since it is handheld, it can be readily positioned and manipulated for a variety of visual applications. The Ocutech Field Viewer is provided with a neck strap and case.
The Ocutech Field Viewer is held at arm’s length and reduces the size making it easier for individuals with constricted visual fields to travel more safely and locate objects beyond their normal field of view.
The Ocutech Field Expander 0.5x (FE) minifies the image by 50% allowing the individual with tunnel vision (restricted visual fields) to see more in the same amount of space. It provides an undistorted, sharp and wider-than-normal field of view in a compact and lightweight design.
It can be prescribed for one or both eyes using the SightScope Compact System in either the frame mounted or clip-on versions, or for one eye with the InstaMount version by using the self-adhesive flanges provided with each device (adhesive flanges recommended for non-AR coated lenses). A convenient reusable demonstrator clip is available for testing and evaluation purposes.