Blue fields and white blood cells

"The blue field entoptic phenomenon is the appearance of tiny bright dots moving quickly accross squiggly lines in the visual field, especially when looking into bright blue light." Fast moving red blood cells in capillaries overlying the retina efficiently absorb blue light, creating a dark web in the visual field which the brain learns to constantly ignore and filter out. Slower moving white blood cells in these capillaries are poor at absorbing blue light, and thus manifest as the bright dots in the visual field.