We tested three lenses (16mm, 25mm, 35mm) on the EyeLink 1000 Plus to find the minimum eye-to-screen distance that still allows successful calibration while maintaining at least 15° of visual angle in the smallest dimension. The 16mm and 25mm lenses allowed the closest distances (330–335 mm to the screen top), while the 35mm lens required 457 mm. All configurations achieved average validation accuracy under 0.30°. Code and data: github.com/mh-salari/eyelink_min_distance_etra_lbw.
How Close Can You Go? Minimum Eye-to-Screen Distance for EyeLink 1000 Plus
