A display panel, a method for adjusting a grayscale of the display panel, and a display device are disclosed. The display panel includes: a first substrate and a second substrate opposite thereto, and a liquid crystal layer therebetween. At least a first electrode assembly is provided on a surface of the first substrate facing towards the liquid crystal layer, and is configured to drive liquid crystal molecules in a first region of the liquid crystal layer abutting against the first electrode assembly to deflect to form a first lens having a first refractive-index distribution, and at least a second electrode assembly is provided on a surface of the second substrate facing towards the liquid crystal layer, and configured to drive liquid crystal molecules in a second region of the liquid crystal layer abutting against the second electrode assembly to deflect to form a second lens having a second refractive-index distribution.