INTRODUCTION
Humans have sight and hearing limitation. Without any devices, our sight and hearing was limited. Most of the limitation of sight can be overcome with the help of certain optical instruments such as magnifying glass, microscope, binoculars and others. The range of frequency of hearing in human 20 Hz to 20 000 Hz. It was different according to the age of a person. Hearing limitations can be overcome by using devices such as microphone, stethoscope, earphone and PA system. All of these devices help us to make our live easier.
OBJECTIVE
The objectives of learning about the limitation of sight :
- I have learnt that our sight and hearing has its limitation.
- I have learnt we can overcome the limitation of our sight and hearing by using technology devices.
The technology devices have make our life easier :
- Teachers use microphone in the assembly.
- Doctors use stethoscopes to hear our heartbeats.
Limitation of sight
Can you see the craters on the moon or a microorganism with your naked eye? How about the bones and organs inside your body? It is not possible for the eyes to see very distant objects or very tiny organisms. We also cannot see through opaque objects. These are some of the limitations of sight.
Optical Illusion
An optical illusion (also called a visual illusion) is characterized by visually perceived images that differ from objective reality. The information gathered by the eye is processed in the brain to give a perception that does not tally with a physical measurement of the stimulus source. There are three main types: literal optical illusions that create images that are different from the objects that make them, physiological ones that are the effects on the eyes and brain of excessive stimulation of a specific type (brightness, colour, size, position, tilt, movement), and cognitive illusions, the result of unconscious inferences.