How does the media affect our perception of reality?
To answer this question, is necessary to establish the context of your question. Since you mention the perception of reality, I assume you are talking about media that discuss current events and news. T's also necessary to understand that different forms of media portray information in different ways. These different modes of communication affect people in different ways as well.
The idea that our perception of reality can be affected by media portrayals is related to the way that different forms of mass media can manipulate or otherwise enhance factual information. Media that combine visual and audio components, for example, make it possible to create a narrative that engages our senses and emotions. For this reason, we generally accept that watching the news on television might be a more emotionally manipulative experience then reading the same story in a newspaper or hearing it on the radio. Television engages our sight and hearing, whereas print is visual, and audio, radio for example, engages only our hearing.
It is also true that television is frequently a vehicle for fictional narrative, and our television news often creates dynamic presentations of the news to engage our attention and to attract viewership. Is it possible that we don't always distinguish between fictional narrative and news reports? The news networks do seem to blur this line sometimes, offering dramatic spectacle to drive up ratings and thereby increase their advertising revenue.
In recent years, newspaper readership has declined greatly. Also many people tend to get their news via the Internet, where it is also possible to receive News with audio and visual components, because TV and radio have websites that make up their broadcasts available. It seems far more likely that people receive their news via more dynamic forms of media, and the critical thinking and analysis that are usually part of reading print news stories are now replaced by a more passive reception of news from these other forms of media.
Internet based news stories are often at least partially in print form, but contain images and audio or video clips to enhance the experience. These articles are also most often shorter in length than print newspaper articles, and so do not provide the same depth of information, and this can also affect our perception of factual elements. It is common to hear the sarcastic statement "I saw it on the internet so it must be true," and this refers to the tendency for unreliable information to be disseminated in the same way as factual information, with little effort made to distinguish the difference. It has become not uncommon for people to say that mainstream media ("MSM") is in the business of distorting the truth. These are all disturbing trends that relate to the idea of media and its impact on our perception of reality.