Digital TV menus can be complicated, the study said

Elderly and short-sighted people find it "laborious and demanding" changing channels, according to research group Generics' Dr Jeremy Klein.

"Unless improvements are made, then about two million people will not easily be able to use digital TV in its current form," he said.

It said people unused to computers were at a particular disadvantage.

Dr Klein said digital TV used many of the same principles as computers.

"That's fine if you've had experience of PCs, but not everyone has. Some people simply cannot understand how to work the equipment and are scared that they will make mistakes," he said.

'Complicated'

"To change channels on an analogue TV you normally have to press just one digit on the remote control. On digital TV you can change channels in several different ways."

Dr Klein said that viewers struggled to remember two or three digit channel numbers, and so often used the up or down buttons on remotes, which took longer to find the channel.

"Or you can use the electronic programme guide (EPG), but this presents problems for people with impaired sight, not to mention the fact that EPGs can be complicated," he added.