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.
The cause of Alzheimer's disease is poorly understood. About 70% of the risk is believed to be genetic with many genes usually involved. Other risk factors include a history of head injuries, depression, or hypertension. The disease process is associated with plaques and tangles in the brain.