LEA Contrast Sensitivity Tests

Low Contrast Visual Acuity Charts

#253700 – #254100 and #271500 – #271900 Testing is identical to the measurement of visual acuity at high contrast level, i.e., we measure the smallest size of the optotypes that the person can recognize. The threshold is defined as the line on which at least 3 out of the 5 optotypes are correctly recognized. The… Read more »

Low Contrast Face Test for Communication Distances

#253500 At the age of 12 weeks at the latest, infants respond to a friendly smile with a happy “social smile”. Their mirror neuron system makes it possible to “mirror” facial expressions if the baby can see facial features clearly enough to copy them. Therefore, if an infant does not respond to smiling faces, eyes… Read more »

LEA SYMBOLS® Low Contrast Test, 10M

Low Contrast Test10M Symbol Size#251100 – #251200 LEA NUMBERS®Low Contrast Test10M Number Size#270400 – #270500 If you did not read about the introduction to contrast sensitivity measurements, we can cover some of the important facts before we discuss the tests. Contrast is defined as luminance difference between two adjacent surfaces, i.e. if one surface reflects… Read more »

Introduction to Contrast Sensitivity

Measurement of contrast sensitivity has been used in experimental and clinical research for several decades, in some places also in routine examinations of patients with different vision problems, especially diabetes, multiple sclerosis, glaucoma, macular degeneration, and brain damage related vision loss. The use of contrast sensitivity measurements is still limited, which may lead to misunderstanding… Read more »