How well can you see?
Eyesight is the ability to see something clearly. It is important to identify abnormalities in vision as early as possible. Good eyesight has a great bearing on children's learning.
Discover the sharpness and range of your vision.
Compare your sight with other people's sight.
Pick up any textbook, and open any page. Bring it closer and closer to your eyes. Can you read it clearly? Take the book farther and farther away from your eyes. Can you read it clearly? What is the nearest distance between you and your book at which you can read clearly [this distance is known as the distance of near vision]? What is the distance, beyond which you cannot read the same page? Are these distances the same for everybody in the class?
Mark a 2mm black dot at the centre of a white card. Similarly on identical looking white cards, mark black dots of 4mm, 6mm, 8mm, 10mm respectively. Draw a long line on the ground. Stand at one end and ask your friend to stand at the other end. Show each marked card together with a blank card to your partner. Ask him/her to move forward along the line and stop when he/she can see the mark. Measure the distance between the two of you. Repeat the same for all cards and all classmates. Tabulate your results. What do you find? Who do you think can see best? Why?
Draw a circle of radius 30 cm from the edge of your bench. Kneel down and put your chin on the bench at the centre of the circle. Look at a spot directly in front of you. Your partner will bring a pencil round the circle from behind your head. Say when you first see the pencil. Your friend will mark the position of the pencil on the circle. Repeat form the other side. Mark the second spot. The angle at your eye formed by the two spots is the angle of your vision. What happens if you repeat the whole experiment with only one eye open? What is the result for the left eye? What is the result for the right eye?
Line up a pencil with the edge of a window or a doorframe keeping both eyes open. Close your right eye. Open it. Now close your left eye. Usually the pencil jumps sharply to one side when one of the eyes is closed. This is the eye that was used to line up the pencil, and the eye that is used most. How many children in your class have right eyes that are dominant? How many children have left eyes that are dominant? Are left-eyed people left-handed?
How will you find out if your eyesight is normal?
What are the common eye defects?
How can the common eye defects be corrected?