GetLenses used a Specsavers ad that compared prices with Boots Opticians. The ad was defaced with a marker pen to include GetLenses' prices, which were lower than those at Specsavers.
Specsavers objected to GetLenses infringing their copyright by using the ad, and for "unlawful comparative advertising".
GetLenses sent the doctored ad via email and put it on the getlenses.co.uk blog.
GetLenses has now removed the offending ad.
Michael Kraftman, CEO of GetLenses, said; "This is interesting as they [Specsavers] were comparing prices in the same way. We have taken the doctored ad down, but have posted a new piece where the essence of the price comparison has stayed up."
Specsavers set a deadline of Friday 8 April for GetLenses to respond to their demands. In their letter, lawyers on behalf of Specsavers said "[GetLenses is] seeking to denigrate and tarnish our client's brand" and "taking advantage of Specsavers' extensive reputation as a value for money optician".
Richard Holmes, Specsavers marketing director, told Marketing: 'This is simply a question of protecting our well-known property "Should've gone to Specsavers".'