An optical illusion (also called a visual illusion )
is an illusion caused by the visual system and characterized by a visual percept that arguably appears to differ from reality. Illusions come in a wide variety; their categorization is difficult because the underlying cause is often not clear but a classification proposed by Richard Gregory is useful as an orientation. According to that, there are three main classes: physical, physiological, and cognitive illusions, and in each class there are four kinds: Ambiguities, distortions, paradoxes, and fictions. A classical example for a physical distortion would be the apparent bending of a stick half immerged in water; an example for a physiological paradox is the motion aftereffect (where, despite movement, position remains unchanged). An example for a physiological fiction is an afterimage. Three typical cognitive distortions are the Ponzo, Poggendorff, and Müller-Lyer illusion. Physical illusions are caused by the physical environment, e. g. by the optical properties of water. Physiological illusions arise in the eye or the visual pathway, e. g. from the effects of excessive stimulation of a specific receptor type. Cognitive visual illusions are the result of unconscious inferences and are perhaps those most widely known.
Aid in Teaching. This websites can aid the parent or educator in teaching as you can search for printable coloring sheets to reinforce the lessons being taught. Children are often able to understand the lesson after many forms of teaching. Adding a coloring project to learning the alphabet or shapes will help reinforce the lesson in a fun way that children will enjoy. Coloring pages help a child to develop better fine motor skills as well as hand eye coordination. You might wonder if colouring inside the lines is important, yet you will soon realise that it is when you see your children use the same skills when playing sport. Creativity is your children's greatest achievements particularly when coloring online. Children gradually start to create their own images, style and color online. Children will often find numerous ways to be creative both on and offline. Experience and creativity is education and learning for everyone. If children are creative they will likely be open to new ideas and educational experiences. Of course it takes a little bit of creativity to get the coloring page activity to be fun. For example if there is a festival just round the corner then get your kid all the coloring pages related to the festival. That way he or she can lean about all the festivals. Make sure to make this fun and interesting by inviting other friends of his age group to your home and have a nice contest among them. Better still tell them to create images of the festival activities and let them exchanges those drawing sheets with each other for coloring. Best of all of course are free pages that can be printed out at home any time you like. There is so much variety obtainable that as long as they have their pages and something to color with a child will never get bored. For many children, there is no greater gift they can give to Mom or Dad than a picture they coloured all by themselves. Inside or outside of the lines, any page coloured with love and happiness is a masterpiece.