Vanishing optotypes. New type of acuity test letters.

@article{Frisn1986VanishingON,
  title={Vanishing optotypes. New type of acuity test letters.},
  author={Lars Fris{\'e}n},
  journal={Archives of ophthalmology},
  year={1986},
  volume={104 8},
  pages={1194-8}
}
Acuity test letters generated on a television monitor were studied with regard to detection and resolution thresholds, both for the native configurations and after high-pass spatial frequency filtering. Comparisons were made with printed acuity charts of different contrast. Filtering diminished the interval between detection and resolution thresholds. Under some circumstances, a small (1 dB, about 26%) increment in size could make a previously invisible optotype clearly visible, or vice versa… CONTINUE READING