Cataract surgery improves contrast as well as acuity. However, not all intraocular lenses provide the same level of contrast. The improvement in contrast is greatest with the single focus lens, and less with the multifocal lens.
The pictures below demonstrate the contrast you might achieve with a standard monofocal lens on the left, compared with a multifocal lens on the right.
These photographs are estimates. The actual amount of contrast lost with multifocal lenses varies between individuals and may be different depending on the task and surrounding lighting.