Perception can make a liar out of the most honest person. What YOU see is not necessarily the same thing someone else sees.
The way you present your scenes, the words your characters use, and their physical movements will help your reader “see” the action. Change the presentation a little bit and you will also change what and how they are seeing it.
If you present a character who is saddened by a loss but keeping an obvious “stiff upper lip” while being kind to those around, you reader will feel differently than if you present that same character with the same loss who whines and snaps at folks around. The first version is much more likely to receive sympathy while the second may try your reader’s patience and understanding.
Take a small cabin in the woods and describe sunlight streaming in and the inside will seem warm and inviting; take the same small cabin and describe it as dark and damp and suddenly it feels forbidding. By altering the reader’s view, even by just a bit, you will alter their perception and make them feel differently about your story.
Letting your readers see the action through a character’s eyes may completely change their viewpoint. If Harry consistently sees gloom and doom then chances are anything seen through his eyes will seem murkier and dismal; however id Sally is an eternal optimist who always manages to see the positive of everything, your readers who see the scene through her eyes will see a much more hopeful and encouraging world.
Choosing your words carefully can also change the reader’s perception. There are several real estate jokes which illustrate the way words change the way we see things. Picture this house: original designer kitchen, near transportation, low maintenance yard, lakefront property, new roof, etc. Doesn’t that sound appealing?
Now imagine this: the original designer kitchen is a 1978 design and the drawers and cupboards squeak on the original hardware; near transportation sounds great until those trains pull into the train yard and toot their horns every night as you try to sleep; it’s a low maintenance yard because no one can use it on the deep slope; the lake front property is prone to flooding as the river flowing into the lake overflows its banks; and finally the new roof is a repair to a major leak which caused extensive water damage to the walls.
Coloring the way your reader views the world you create either by using a character’s unique perspective or by the descriptions you assign can elicit different emotions and reactions. You can also use the character’s perspective to establish his personality – What if he is the only one that sees ugliness while everyone else sees bright promise? Your reader will probably come to think of that character as a grouch. Perspective makes it possible for two or more characters to share the same memory in totally different ways and yet each believe that their recollection is correct.
Writing exercise: Write a few paragraphs describing a man going into a diner, ordering breakfast, eating it, paying the bill and leaving. 1) Write this from the perspective of a man who woke late and is rushed to get on his way. 2) Write this from the perspective of a man who just started his vacation and relaxation time and is looking forward to doing sightseeing. 3) Write this from the perspective of a man who just lost his wife and this was her favorite diner. 4) Write this from the perspective of a man who is nervous about a business meeting that is a sure thing to make him wealthy.
Writing prompt: List ten excuses to use in turning down a marriage proposal, try not to be unkind. List ten reasons for a manager to hire you for a job without a resume or job experience. List ten things you would do if you won a multi-million dollar lottery.

