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ABSTRACT
We describe an alternative glare test using a simple penlight. When the glare and decrease in vision created by the penlight were compared on Snellen chart recordings, 92% of eyes within 20/50 or less visual acuity were no longer able to see even the 20/200 Snellen figure. This penlight test is suggested as an adjunct to standard Snellen testing in the evaluation of the cataract surgery patient.
There have been a number of reports concerning the inadequacy of Snellen chart measurements for grading cataracts and the indications for cataract surgery. The evolution of broadened indications for cataract and intraocular lens surgery has taken an orderly, although rapid, pathway. The recent dramatic improvement in cataract surgery success rates has increased confidence and lowered the "Snellen" threshold as an indication for cataract surgery. The advancements of modern technology have aided the patient with disability from cataracts, as opposed to the patient with a poor "Snellen" acuity.
The glare created by various types of cataracts in eyes with 20/40 or better "Snellen" vision has been described carefully by Nadler and Jaffe.1·2 When a cataractous eye is evaluated, the patients disability must be noted. How often do we note the uncanny difference in visual impairment in several patients with the same measurable acuity? Objective glare tests such as the Miller-Nadler instrument (Titmus, Petersburg, Virginia) are helpful and most valuable when used to evaluate a patients visual function. In particular, glare testing is beneficial in evaluating patients with 20/30 and 20/40 vision and numerous complaints.
Most practitioners use standard Snellen and Jaeger measurements in a well-lighted examining room and depend on clinical symptoms and signs. We have found a simple penlight test helpful when evaluating natural visual function within the physical confines of the examining room.
METHODS AND MATERIALS
One hundred fourteen eyes were examined in the usual fashion, which included a complete examination with standard Snellen visual acuity measurements. The average patient age was 71.6 years. The vision was measured at 20 feet with standard room illumination. Immediately afterward, a simple disposable penlight was shone directly into the patients eye at a 15 to 30° angle from the temporal aspect 12 to 18 inches from the patient (Figure). The visual acuity test was repeated and recorded...