1) circular blur effect

环状暗斑效应
1.
Light field circular blur effect on liquid surface and refraction index measurement;

液体表面光场环状暗斑效应及折射率测量
2) ring scotoma

环状暗点
3) urban dark island effect

暗岛效应
4) dulling effect

暗晦效应
5) dimming effect

暗淡效应
6) twilight efficiency

昏暗效应