Albus could see it all however, his walls told him the truth. He was a patient and powerful wizard, the dementors didn't even affect him now. What those walls didn't show was Albus' reflection, otherwise he would perhaps have realised he didn't have those years available.
His tongue, lips and beard were all black. With Dumbledore's skin resembling dried leather and his eyes were almost continually bloodshot and itchy, the diagnosis was not good.
It was a good few years before a visiting healer picked up what was happening here. In licking the back of those articles that were festooned on his cell walls, Dumbledore was ingesting trace amounts of the inks used to print the newspaper. Since these inks contained things you didn't want in your body, predominantly lead, Dumbledore had been slowly but surely poisoning himself.
When they stopped delivering his daily paper, the withdrawal symptoms experienced by the prisoner might have been mainly psychological but they were real none the less. A decision had to be quickly made. The effects of the lead were cumulative and the metal couldn't be flushed from a person's body. They also affected a wizard's mental capacity, and Dumbledore was already badly poisoned.
As Dumbledore was going to be here for the rest of his life, and the lead in his system actually protected him from the debilitating dementor effects - because it was already working on his brain - a decision was reached to let him have his newspapers again. This stopped all the stress that not having his newspapers was causing Albus, and no one really knew whether the immediate high levels of stress or continual slow poisoning was worse for his ancient heart.
If Dumbledore really was the dark lord of that prophecy then it could easily be construed that he would eventually die from Harry's hand, since it was him who paid for the Daily Prophet subscription. It was also decided at ministerial level never to tell Harry about this, he had already rid them from one dark lord.
Albus Dumbledore was now drifting deeper and deeper into his own fantasy world, somewhere not even the dementors could reach. He was a thin and wizened old man who rattled about in his cell, one who was not long for this world. When an inmate died in prison, they were buried on the island. One thing was certain, Albus Dumbledore was never leaving Azkaban. This would be his home and final resting place.