BAT, the Brightness Acuity Tester is a handheld instrument designed for two major visual function tests:
 
1) Brightness Acuity Test
Many people with cataracts and other ocular media opacities are visually disabled in bright light conditions from intraocular light scatter often referred to as glare. The BAT Brightness Acuity Tester provides objective measurements of functional visual acuity in three common bright light conditions
while the is in the standard refracting lane.
 
2) Macular Photostress Test
The BAT Brightness Acuity Tester produces a full hemispherical light source to photostress the retina when maculopathy is suspected.
BRIGHTNESS ACUITY TEST
Clinicians are acutely aware of the disparity between functional vision in bright light conditions compared to that measured in a standard dark refracting lane. Significant
disparity usually occurs with opacities or distortions in the ocular media such as:
 
1) Corneal opacities, e.g. corneal scars or irregularities.
2) Lenticular opacities, e.g. anterior subcapsular, posterior subcapsular and nuclear sclerotic cataracts.
3) Posterior capsular opacification following extracapsular cataract surgery.
4) Vitreous opacities, e.g. dense central vitreous floaters or asteroid hyalosis.
 
These phenomena are frequently described as glare producing conditions. The BAT Brightness Acuity Tester can simulate three bright light conditions:
 
1) High-direct overhead sunlight;
2) Medium-partly cloudy day;
3) Low-bright overhead commercial lighting.
 
The visual acuity measurements will be similar to those that would be measured in these three conditions using a standard eye chart ¹. The result is an assessment of functional visual acuity which can be obtained in the standard refracting lane.