Brightness Acuity Meter (BAM) Triple Function Glare Tester
mimics flood lighting
3 lighting levels
AA batteries (2)
accepts lens holder
made in USA
1 year full warranty
Illumination sources can adversely reduce visual acuity by degrading image resolution when light scattering eye conditions exist. The effect of glare on visual acuity is measured with the BAM™.
High contrast or graded contrast images may be used as test targets. Standard lighting brightness of the test targets is recommended (85 cd/m2).
The BAM™ brightness and acuity levels can be tailored to meet the needs of the examiner. Several brightness levels can be tested or testing can be limited to one brightness.
Conditions where glare adversely affects acuity:
¨◘ Corneal opacities or corneal edema
◘ Cataract, particularly posterior sub-capsular opacities
◘ Clouding of the posterior lens capsule
◘ Opacities in the vitreous
◘ Scratched or dirty glasses or contact lenses
BAM is primarily a glare tester, however, due to the lighting parameters, macular photostress and the entoptic phenomenon of flying corpuscles can be tested.
The diffuse lighting for the BAM is similar in principle to the hand-held Brightness Acuity Test (BAT)1 manufactured by MARCO Ophthalmic, Inc..
The BAM provides an alternative to the BAT for those clinicians accustomed to diffuse background glare testing. Like the BAT, the BAM has three levels of background illumination in a hemispheric bowl that is held close to the eye. As a result, one possible source of error is pupil constriction by the illuminator; certain patients with cataract perform better with pupil constriction, thereby giving a false-negative test2. Conversely, the third level (brightest) is dazzling, inducing false-positive results2 .