Original sentence: Afshar now places a grid of thin wires just before the lens (Fig.Afshar then claims that he can check for the wave characteristics of the light in the same experiment, by the presence of the grid.Consequently, one would expect that the image quality is reduced, as is indeed observed by Afshar.If one of the pinholes is blocked, the interference pattern can no longer be formed, and some of the light will be blocked by the wires.These wires are placed in previously measured positions of the dark fringes of an interference pattern which is produced by the dual pinhole setup when observed directly.When the light acts as waves,  because of interference one can observe that there are regions that the photons avoid, called dark fringes
Edited sentence: Afshar attempts to check for the wave characteristics of the light in the same experiment by placing a grid of thin wires just before the lens.If one of the pinholes is blocked, the interference pattern can no longer be formed, and some of the light will be blocked by the wires, and the image quality would be reduced (Fig.These wires are carefully placed in previously measured positions of the dark fringes of an interference pattern which is produced by the dual pinhole setup when observed directly.When the light acts as waves, instead of particles, there are regions that the photons avoid, called the dark fringes