(i) Don't Rub eyes.
(ii) Wash them properly and softly.
(iii) Get your eyes checked regularly by doctors.

(a) Humanitarian value of giving way to AMBULANCE so that any patient can immediately reach to the hospital.
(b) Because any person driving the vehicle which is ahead of the Ambulance van, can see the laterally inverted alphabets correctly from his rear view mirror & make way for it to pass through.
(c) Characteristics of Image formed by Plane Mirror:
(1) Virtual & Erect.
(2) It is of the same shape & size.
(3) It is at the same distance behind the mirror as the object is in front of it.
(4)It is formed behind the mirror.

Difference between real and virtual image:

Take a circular cardboard disc of about 10 cm diameter. Divide this disc into seven segments. Paint each segment with the seven rainbow colours, as shown in the following figure. Make a small hole at the centre of the disc. Fix the disc loosely on the tip of a refill of a ball pen. Rotate the disc at a high speed. All the colours get mixed up and the disc will appear whitish. Such a disc is popularly known as Newton's disc.

Take three cardboards of similar size and make a hole in the centre of each. Make sure that the size and position of the hole is the same in each cardboard.
Now put the three cardboards in vertical position with the help of bricks in such a way that the holes in the three cardboards are in a straight line. Place a lighted candle in front of the cardboard no. 1 as shown in Fig. Look through the hole of the last cardboard no. 3.

The flame can be seen clearly through the holes. When one of the cardboards is slightly raised, no flame can be seen. This shows that light travels in a straight line. No flame can be seen when the holes of the three cardboards are not in a straight line because light can not bend.

(i) Convex mirror.
(ii) The image formed is virtual, erect and smaller than the size of the object.
(iii) The size of the image will increase as the object is moved closer to the convex mirror but is never larger than the size of the object.

(i) Concave lens.
(ii) The image formed is erect, virtual and diminished.
(iii) The characteristics of the image will not change on changing the position of object.

(a) Plane mirrors are used as looking glasses. They are also used in solar cookers, periscopes and kaleidoscopes.
(b) Concave mirrors are used as reflectors in the headlights of automobiles. As these give erect and magnified images, these are used by doctors to examine parts of bodies, such as ear, nose, throat etc.
(c) Convex mirrors can be used to view a much larger area than is possible with a plane mirror. These are therefore used as rear view or side view mirrors in cars and scooters.

Since, the image is 6m away from the plane mirror. So, it means that the object is also 6m away from the mirror.

[Because OP = PI]
So, when the person moves 2m towards the plane mirror, then the distance between the person and the plane mirror will be equal to (6 m- 2 m)= 4 m, this means that distance between the image and the mirror will be 4m.

The distance between the person and his image = PO'+ PI' = 4 + 4 = 8 m

In case of mirror, the image formed by it is laterally inverted, i.e. left seems to be right and right seems to be left. So, in ambulance there is emergency for patients to reach hospital and by viewing in rear mirror, it can be easily identified of a vehicle and everyone give him a way.

No, he will not observe band of seven colours because laser light consists of monochromatic light of single colour. But seven colours of bands are only observed, when a white light is passed through a prism and dispersion takes place.

(a) The image which can be formed on the screen is real image.
(b) The image which cannot be formed on the screen is virtual image.

If the reflecting surface of a torch got rusted, it produces diffused light with lower intensity and the objects are not clearly visible in this diffused and lower intensity of light.

These mirrors can be differentiated by bringing our face close to each mirror turn by turn. Since, a plane mirror will produce an image of the same size as our face while a concave mirror will produce a magnified image and our face will look much bigger and on other sides, a convex mirror will produce a diminished image and our face will look much smaller like a small child.

A concave lens always forms a virtual image