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Portable Refractor Unit*
NOTES CASES INSTRUMENTS PORTABLE REFRACTOR UNIT* G. PETER HALBERG,
M.D.
New York Many ophthalmologists still have the old De Zeng type refractor in their offices. I found that the refractor cells of this instru ment fit the palm of the hand comfortably (glove size 7l/>) and practically without any further transformation (except a rather delicate dismantling and cleaning job) a sin gle refractor cell can be used as a quite flexi ble aid for retinoscopy, providing a fairly complete battery of lenses. Each refractor cell contains four inde pendent lens-discs. Disc 1 contains the fol lowing lenses: +0.25, +0.50, +0.75, +1.00, + 1.25, +1.50, +1.75. Disc 2 contains a -0.25, -0.50, -0.75, -1.00, -1.25, - 1 . 5 0 , - 1 . 7 5 . Disc 3 contains a +2.00, +4.00, +6.00, - 2 . 0 0 , - 4 . 0 0 , - 6 . 0 0 , -8.00. The examiner easily manipulates Discs 1, 2, and 3 by the index finger or thumb. Direct reading of the lens values is quite satisfac tory. A fourth auxiliary disc contains the fol lowing lenses: +8.00, -10.00, +0.12,
Fig. 2 (Halberg). Instrument in use.
Fig. 1 (Halberg). ( A ) Patient's side. ( B ) E x aminer's side. ( C ) Side view of instrument.
—0.12, and a +1.50 lens for retinoscopy at 66 cm. All lenses are spheres of good optical qual ity. They can be used individually or in com binations. Recently a wooden tool handle, painted with black lacquer, was added. The total weight of the instrument is less than one pound (10% ounces). It is a handy unit to have in the medical bag for clinic or bedside use. In the office, in addition to its use for ret inoscopy, it is helpful in the selection of strong reading additions for low visual acu ity cases. 936 Fifth Avenue (21).
* Aided by a grant from the Ophthalmological Foundation, Inc. 218
ACKNOWLEDGMENT
The technical assistance of Mr. Frank Fencl, Old Brookville, New York, is gratefully acknowledged.
M.D.
New York Many ophthalmologists still have the old De Zeng type refractor in their offices. I found that the refractor cells of this instru ment fit the palm of the hand comfortably (glove size 7l/>) and practically without any further transformation (except a rather delicate dismantling and cleaning job) a sin gle refractor cell can be used as a quite flexi ble aid for retinoscopy, providing a fairly complete battery of lenses. Each refractor cell contains four inde pendent lens-discs. Disc 1 contains the fol lowing lenses: +0.25, +0.50, +0.75, +1.00, + 1.25, +1.50, +1.75. Disc 2 contains a -0.25, -0.50, -0.75, -1.00, -1.25, - 1 . 5 0 , - 1 . 7 5 . Disc 3 contains a +2.00, +4.00, +6.00, - 2 . 0 0 , - 4 . 0 0 , - 6 . 0 0 , -8.00. The examiner easily manipulates Discs 1, 2, and 3 by the index finger or thumb. Direct reading of the lens values is quite satisfac tory. A fourth auxiliary disc contains the fol lowing lenses: +8.00, -10.00, +0.12,
Fig. 2 (Halberg). Instrument in use.
Fig. 1 (Halberg). ( A ) Patient's side. ( B ) E x aminer's side. ( C ) Side view of instrument.
—0.12, and a +1.50 lens for retinoscopy at 66 cm. All lenses are spheres of good optical qual ity. They can be used individually or in com binations. Recently a wooden tool handle, painted with black lacquer, was added. The total weight of the instrument is less than one pound (10% ounces). It is a handy unit to have in the medical bag for clinic or bedside use. In the office, in addition to its use for ret inoscopy, it is helpful in the selection of strong reading additions for low visual acu ity cases. 936 Fifth Avenue (21).
* Aided by a grant from the Ophthalmological Foundation, Inc. 218
ACKNOWLEDGMENT
The technical assistance of Mr. Frank Fencl, Old Brookville, New York, is gratefully acknowledged.