The Human Eye And The Colourful World

Que 1. News spread in the school that a student of Class IX-A has expired due to heart attack, but he has donated his beautiful eyes to one of his friends. All the members of school felt very sad for his untimely death, but on the other hand they were overwhelmed on hearing the donation of his eyes to his friend, who would now be able to see this beautiful nature.

Answer the following questions based on the situation given above. 

(i) Do you think that the student who expired had done good job? Is it worth to donate vital organs? 

(ii) What values are promoted here? 

(iii) What other organs can be donated after dying?

Ans. (i) Yes. Donating vital organs can make the life of a living person easier. 

(ii) Social welfare, kind-hearted, selfless, friendship. 

(iii) Kidneys, heart, liver, etc.

Que 2. On the rainy day, Ram reached his grandfather's place in village. On the way to house he saw a beautiful rainbow in the sky. In night, he saw lots of twinkling stars in the clear sky. He was very excited to see these beautiful natural phenomena, which he was not able to see in the city, where he lived with his father.

Answer the following questions based on the situation given above. 

(i) Do you think that pollution in atmosphere affects the formation of rainbow and twinkling of stars? 

(ii) Do you agree with the fact that pollution-free environment will strengthen such natural phenomena in the cities as well? 

(iii) What steps can be taken so that the natural phenomena can be enjoyed in cities as well?

Ans. (i) Yes. Though rainbow formation and twinkling of stars are the phenomena of light but these won't be visible if there is a lot of pollution in the stratosphere. 

(ii) Yes. 

(iii) Keeping the city clean and pollution-free, plant more trees.

Que 3. Sania and Shreya are best friends and study in grade 4. Recently, Sania has been facing difficulty in reading the blackboard text from the last desk. Shreya is little uncomfortable and wonders why Sania complains sitting on the last desk. On observation she found that Sania often carries junk food in her lunch. Shreya has started sharing her lunch – full of green vegetables and fruits with her. Sania is now better and has also started taking a 'balanced diet’.

Answer the following questions based on the above situation: 

(i) Name the eye defect Sania is suffering from? What are the two possible reasons related to her eye defect? 

(ii) What value is displayed by Shreya and Sania? 

(iii) How can this value be promoted? Suggest one activity.

Ans. (i) Myopia/short sightedness. Lens defect (increased thinness), eye ball defect (elongation). 

(ii) Friendship, concern for each other, appreciation for balanced diet. 

(iii) Sharing common things; helping each other in studies.

Que 4. A team of eye specialists visited a village and examined number of villages for any vision defects. They observed that many villagers suffered from different defects of vision. They left and came back after a month with required medicines and equipment for treatment. The eye treatment camp continued for one week. The doctors as well as villagers were extremely happy after the event.

Answer the following questions based on the above information: 

(i) Which values made the doctors happy? Name any two actions on your part as an individual which you can take to get similar kind of happiness in other everyday life situations. 

(ii) Assuming yourself to be a doctor in this event, suggest one more help or action related to eye defects to help the villagers further.

Ans. (i) Empathy, service to others, concern for fellow beings.

Adopting a needy individual or group and contributing towards their free education. 

Spreading awareness about health care. (Any other) 

(ii) Follow-up check-up; awareness about eye-care, free distribution of required spectacles, etc.

Que 5. (a) Write the function of each of the following parts of human eye: 

                               Cornea; iris; crystalline lens; ciliary muscles. 

(b) Millions of people of the developing countries of world are suffering from corneal blindness. These persons can be cured by replacing the defective corner with cornea of a denoted eye. A charitable society of your city has organised a campaign in your neighborhood in order to create awareness about this fact. If you are asked to participate in this mission how would you contribute in this noble cause? 

(i) Sate the objective of organising such campaigns. 

(ii) List two arguments which you would give to motivate the people to donate their eyes after death. 

(iii) List two values which are developed in the persons who actively participate and contribute in such programmes.

Ans. (a) Cornea: Refracts the rays of light falling on the eye. 

Iris: Controls the size of the pupil 

Crystalline lens: Focuses the image of the objects on the retina. 

Ciliary muscles: Holds the eye lens and adjusts its focal length. 

(b) (i) These campaigns are organised to make people aware and realise their duties towards society. 

(ii) Following arguments can be given: 

One person can give sight to two people. 

Our eyes can live even after our death. 

(iii) Values: Concern for others/Responsible behavior/Group work.

Que 6.  Write the importance of ciliary muscles in the human eye. Name the defect of vision that arises due to gradual weakening of the ciliary muscles in old age. What type of lenses are required by the persons suffering from this defect to see the objects clearly?

Akshay, sitting in the last row in his class, could not see clearly the word written on the blackboard. When the teacher noticed it, he announced if any student sitting in the front row could volunteer to exchange his seat with Akshay. Salman immediately agreed to exchange his seat with Akshay. He could now see the words written on the blackboard clearly. The teacher thought it fit to send the message to Akshay's parents advising them to get his eyesight checked.

In the context of the above event, answer the following questions: 

(a) Which defect of vision is Akshay suffering from? Which type of lens is used to correct this defect? 

(b) State the values displayed by the teacher and Salman. 

(c) In your opinion, in what way can Akshay express his gratitude towards the teacher and salman?

Ans. Ciliary muscles adjust the curvature of the eye lens and change its focal length. Weakening of ciliary muscles leads to presbyopia. This can be corrected by a bifocal lens. 

(a) Akshay is suffering from myopia or near-sightedness. A concave lens can be used to correct this defect. 

(b) The teacher displayed presence of mind and pro-activeness, and a considerate nature. 

Salman displayed the virtue of friendship and caring nature. 

(c) Akshay should thank the teacher and Salman in front of the entire class.