I'd like to point something out. I'll keep it general. There are two way to be blind. One is through the sensory organ (the eyes) not working, and the other is through the actual part of the brain for vision (visual cortex) not working. (Obviously there are degrees of "not working").

If a person is blind because their sensory organ doesn't work, they still retain the ability neurologically to have vision, because of this they would actually experience "darkness" aka seeing black. Now there is also a phenomena that occurs do to our neuroplasticity (neurons wanting to basically grow and search for input impulses and make pathways, and how good they are and making and changing these pathways) that results in parts of the brain not being used for their intended purpose to be rewired for another one. For example neurons in the visual cortex would start dying since they're not being used (the brain thus assumes they aren't needed and doesn't want to waste energy maintaining them). Then neighboring neurons from lets say the motor cortex for example would start creeping in and innervating into that visual cortex part of the brain, which still retains it's "purpose". So now movements or tactile senses could lead to "seeing" things by random impulses that may be read as light/color that of course the brain would try to interpret in natures math which is shapes and what not.

NOW, if the issue is in the visual cortex itself and it can't perform the function it's meant to, then you aren't just seeing darkness... you're not even having the "idea" of vision. This is hard to grasp. It's not even like seeing a void. The best way I can imagine it is if you stick your hand/foot out and try to "see" out of it. It's not "black" like closing your eyes, it's nothingness. You aren't just not getting the signals you are literally not perceiving the concept of vision.

Which is "worse" I don't know. I can't comprehend if it is worst to be in a void or darkness. Perhaps not even having the comprehension of sight slightly helps or maybe it's more terrifying. Fun note, the concept of neurons innervating into other parts of the brain is the real science behind the "if you lose on sense the others take over and enhance", it is to some extent true. Dr. Ramachandran really helped understand this experimentally through his work with phantom limb syndrome

Source- Neurology, although this is in now way my field focus.