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barely visible to the subject under glare conditions. The task was done at all spatial frequencies [49]. Both glare test measured the lowest contrast level visible by the subject to determine their contrast sensitivity. These results were both used to calculate a glare score which was used to

Their shared similarities in testing methods also yielded the same results where both glare tests displayed discriminative ability between cataract subjects and age-matched ocular healthy subjects. However, each study correlated their glare score with different measurements and so each drew their own specific inferences from their results. The Ophthimus Glare Tester study looked at cataract patients in preparation for cataract surgery. These individuals had normal visual acuity, but the results of the study showed their disability glare score to be significantly lower and they also reported visual complaints associated with glare. After the surgery, 24 out of 25 subjects had no self-reported glare problems but some of the subjects still displayed elevated glare sensitivity [21]. This supported the discriminative ability of the Ophthimus Glare Tester that the glare test could still distinguish between cataracts and ocular healthy individuals even after surgery when visual function improved. The validity of the Ophthimus Glare Tester's performance was supported by being relevant to the subjective visual complaints of the subjects as well as with the results of preoperative and postoperative surgery. The CSF glare tester, on the other hand, measured their scores against opacity levels of the cataract subjects. They demonstrated a correlation between the glare scores and the current pathology of each subject [49]. Hence, the validity that the CSF glare tester was based more so on physiological progress of the disease rather than subjective experiences. Both these glare tests exhibited strong discriminative findings but because the studies that utilized the tests based their results on different foundations, the information yielded by each glare testing device was distinctive. This also applied to the information each study provided about the effects of glare on cataracts even though the glare tests shared a number of similarities. And so more testing should be conducted to assess the comparative validity of these glare tests.

Functional vision deficits may occur in ocular healthy individuals and in individuals that have disease. It appears that glare testing can serve as a good indicator of visual function and may also be affected in disease states. As various new treatment modalities become available for age related macular degeneration, glaucoma and newer intraocular lens surgeries and laser refractive surgeries, treatment outcome may be better assessed using visual function tasks that are more difficult to perform and are more realistic of "real" world activities. To this accord a combination of glare testing with contrast discrimination may be well suited. The difficulties arise in lack of standardization of parameters or lack of existence of evaluation standards makes assessing of the glare tests very difficult. There is tremendous need for these standards setting and independent evaluation of these devices before a clinically acceptable standard can be obtained and accepted. It appears that although the glare testing shows huge promise it cannot be utilized clinically as a useful test and currently remains a technique useful for research arena.

understand the visual function of the cataract subjects and ocular healthy subjects.

78 Causes and Coping with Visual Impairment and Blindness

5. Conclusion

My Diep1 and Pinakin Gunvant Davey<sup>2</sup> \*

\*Address all correspondence to: pdavey@westernu.edu

1 Western University of Health Sciences, College of Osteopathic Medicine of the Pacific, Pomona CA, USA

2 Western University of Health Sciences, College of Optometry, Pomona CA, USA
