Driving with Low Vision Bill Takeshita O D
Driving with Low Vision Bill Takeshita, O. D. , F. A. A. O. , F. C. O. V. D.
DMV 962 Form • People with low vision are eligible to apply for drivers license • Requires a special vision examination and the completion of the DMV 962 form by a low vision optometrist or ophthalmologist • Written and road tests
Low Vision Examination • Determine the functional strengths and weaknesses of the patient • Design optical aids to maximize the patient’s remaining vision • Develop treatment program to address functional problems • Work with allied professionals
Eye Movement Testing • Fixation: Ability to keep eyes steady on the target. Nystagmus is the uncontrollable shaking of the eyes. • Versions or pursuits: Ability to follow a moving target (Parietal lobe of brain) • Saccades: Ability to shift the eyes from one target to another, such as when reading. (Front lobe of brain). • Eye-hand coordination testing
Convergence Testing • Convergence is the ability to cross or bring both eyes together when reading. • Poor convergence is a leading cause of the inability to read • Double vision • Headaches • Loss of place when reading
Depth Perception • Photograph of stereo test
Color Vision • Photo of color vision test
Contrast Sensitivity Testing • Photo of Pelly Robson • Photo of Vis Tek
Peripheral Vision Testing • Photo of Humphrey • Test of finger confrontation
Amsler Grid Central Vision Test • Photo of Amsler Grid test
Distance Acuity • Photo of ETDRS • Photo of Feinbloom
Refraction • Illustration of perspective with e on macula
Telescopic Refraction • Specialized technique to determine best spectacle correction • Focus light on the healthiest region of retina for eccentric viewing
Visual Status • World Health Organization and Social Security Administration • Fully Sighted • Partially Sighted • Legally Blind • Functionally Blind
Legal Blindness • Visual acuity of 20/200 or worse in the BETTER eye with glasses or contact lenses • Widest field of vision 20 degrees or smaller in the better eye with corrective glasses or contact lenses • May qualify for audio books, Social Security, transportation discounts, Medicare
Bioptic Telescopes • 4 x Full Diameter TS Not focusable • Spiral focusable TS • Expanded field focus TS (note: length)
Ocutech Bioptic • Cosmetically more appealing • Autofocus option • Slightly dimmer than DVI BTS • Smaller field of view than DVI BTS
Special Lens Materials • • Eschenbach Novus Super Modular Hyper 1. 67 Trivex
Polarized Prescription Filters • Provide the most features for the patient • UV filtration • Eliminate reflected glare from concrete, windshields, water • Many colors to reduce glare but not cut out so much light that one cannot see • Available in prescriptions, bifocals, and progressive addition lenses
UV Shield and No. IR Filters • • UV shields Solar Shields No. IR Spectra Shields
Cocoon Filters • Photo of cocoon filters
Grey Filters • Work well for those patients who are bothered by direct sunlight • Does not distort color vision • May be too dark for some patients • Helpful for mobility during sunny days • Gradient gray tints are also helpful for many patients
Green filters • Bausch and Lomb G-15 • Some patients may prefer this color over the grey lens • Some patients with glaucoma and optic nerve problems appreciate this color lens • G-15 color can be made in plastic • Red/green color deficiency may appreciate the green filter
Blue Free Filters • Brown, orange, amber, and yellow filter the blue wavelengths of light • Corning CPF (glass) • Increase the contrast of images • Some patients may report that things are brighter • Macular degeneration, diabetic retinopathy, retinitis pigmentosa
PRL Training • Teach the patient to move his or her eyes to allow the image to focus on the healthier regions of the retina. • Eccentric viewing training • Takes a lot of time and patience
Macular Scar • Photo of macular scar Can you read this?
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