The IBM T220 and T221 are LCD monitors that were sold between 2001 and 2005, with a native resolution of 3840×2400 pixels (WQUXGA) on a screen with a diagonal of 22.2 inches (564 mm). This works out to 9,216,000 pixels, with a pixel density of 204 pixels per inch, much higher than contemporary computer monitors and approaching the resolution of print media. The display family was nicknamed "Big Bertha" in some trade journals. Costing around $8,400 in 2003, the displays saw few buyers. Such high-resolution displays would remain niche products for nearly a decade until modern high-dpi displays such as Apple's Retina display line saw more-widespread adoption.

Retina display is a branded series of LCDs and OLED displays by Apple Inc. that have a higher pixel density than traditional displays. Apple has registered the term "Retina" as a trademark with regard to computers and mobile devices with the United States Patent and Trademark Office and Canadian Intellectual Property Office. The applications were approved in 2012 and 2014 respectively. The Canadian application cited a 2010 application in Jamaica.