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.
In some types of dementia (such as Alzheimer disease), the level of acetylcholine in the brain is low. Acetylcholine is a chemical messenger (called a neurotransmitter) that helps nerve cells communicate with one another.