Question

how H.G wells uses symbols in the invisible man to make the right impact in the given situation

Answer 1

The Invisible Man as the title suggests uses symbolism in the mention of sight and darkness at different places in the novel. First of all, being invisible means the presence of light or absence of it is insignificant as in both cases it can't be perceived. In the then nineteenth century modern science had barely developed and people were ignorant. When the Invisible man first developed his formula, he had a vision of all that invisibility may mean. Here Wells uses vision figuratively as a symbol to be able to see the future. In contrast, if people are not been able to see the Invisible Man, that connotes their inability to see future. By sight, Wells means science and lot of it. 

Similarly symbol of darkness, dim light suggests ignorance of villagers as they are in the dark, here darkness shows uncertainty. For example, Mrs. Hall sees invisible man  has a gigantic mouth (really just a hole in his bandages). She has doubt about what she has seen because everything was so ruddy, shadowy and indistinct to her, the more so as she has just been lighting the lamp and her eyes were dazzled. When Mr. Hall sees the Invisible Man he thinks he has seen a hand-less arm, but isn't sure because the room is dark. So, dimness signifies uncertainty as they are not sure of what they have seen due to dim lights. It further suggests ignorance on part of everyone there.