The average age for cataract surgery is approximately 73 to 75 years old. But cataracts can occur in the 30s, 40s, and 50s. Of course the older the patient gets the more common the cataracts.
Two neurotransmitters seem to play a role in Alzheimer's Disease: acetylcholine and glutamate. Acetylcholine (ACh) activates muscles and helps with arousal, short-term memory, and learning. Individuals with AD have low levels of ACh.
Alzheimer's disease is characterised by loss of neurons and synapses in the cerebral cortex and certain subcortical regions. This loss results in gross atrophy of the affected regions, including degeneration in the temporal lobe and parietal lobe, and parts of the frontal cortex and cingulate gyrus.