Lloyd James won the brief to market the list following a three-way pitch against undisclosed companies.
Specsavers' data is collected when customers have an eye test and loyalty is said to run at 82%. The database has been profiled to identify key lifestyle and demographic characteristics, showing that the majority of customers are married homeowners aged between 40 and 65, who have lived in their homes for more than 10 years.
Lloyd James will hold the data on its database count tool, which enables counts to be produced immediately and processed within 24 hours.
Andrew Molle, Specsavers marketing director, said: "Specsavers has for the past two years been voted the most trusted brand of opticians by Reader's Digest, who surveyed nearly 40,000 consumers in 18 countries.
"Brand awareness is extremely high and our customers recognise that we offer them the best value-for-money optical service on the high street. So our database can be headlined as being made up of brand-conscious individuals who appreciate a good value-for-money proposition."
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