Did you know that we begin to lose our sight in our 40's? You probably remember buying a pair of annoying reader glasses so you can read close up.
Brain games might not prevent those readers but they will increase your "useful field of view"
Posit Science has a number of products that you can buy, but you can also rent time on a game site like www.lumosity.com
What a great gift to send someone. The power of sight.
You might think of sending your clients a reminder about keeping their vision sharp.