Because this can make them appear more mysterious and more reliable. Let others know that he does not see with his eyes, but calculates with his heart. Another point is that they don’t dare to look into other people’s eyes because they feel guilty, so they poke their eyes to scare them.
When many people go to have their fortunes told, the first thing they look at is the appearance of the fortune teller. They believe that young people are not necessarily liars, but those who wear sunglasses and are older fortune tellers are accurate. Because they think they will be more powerful when wearing sunglasses, because they do not see with their eyes, but calculate with their hearts. Just like people in TV dramas nowadays, very powerful people wear masks. This can not only show their sense of mystery, but also show that they are different from others.
Many people rely on mystery to attract people. For example, if you see a sneaky person on the road, you will want to focus on him, but if you are an ordinary passerby, You won't even look at him. This may be some kind of law. People generally think that those mysterious talents are the most reliable. The beginning of some novels will also be written with the intention of arousing readers' curiosity, because this will make readers more curious to continue reading, instead of reading with a plot that can be understood at a glance.
They may also wear sunglasses because of a guilty conscience. In their profession, they have to tell people’s fortunes without conscience. Since they do so without conscience, they must have a little guilt in their hearts, and then put Prick their eyes and put on sunglasses so they can't see the fortune teller and the fortune teller can't see them. It has never been possible for anyone to predict the future or guess your fate in the future. These are all small tricks, just like magic. They will try their best to describe what happened to you recently. This is because they want you to trust them more and make you feel wow, they are so awesome and they are right. In this way, you will trust those fortune tellers more, then listen to what they say, then take notes, and you may come to this person for fortune telling later.
Fortune tellers worry too much and don’t dare to look at others, which will make them look guilty.