Methods of implementing Visual Impairment Effects

I am wanting to create a simulator that showcases the effects of different types of Visual Impairments, for example Cataracts, Glaucoma, Macular Degeneration, Diabetic Retinopathy, does anyone have any ideas on how I might implement these effects. My ideas were to use post processing effects to create blurred areas in the vision of the player. I don’t have much experience with post processing and was wondering if anyone could offer any guidance on how I might go about this?