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.
Worldwide almost 30 million suffer from Alzheimer's disease. The brains of people with Alzheimer's contain two types of misfolded proteins -- amyloid plaques and tangles of the protein Tau. Whether these protein abnormalities are a cause of Alzheimer's or a consequence of the disease are unclear.