Question

Write short notes on the following : (i) myopia (ii) taste buds (iii) accommodation of the eye

Answer 1

Answer:

here is answer

Explanation:

1.Myopia

Myopia or nearsightedness is a condition in which objects in the distance are blurred either because the eye is too long or too strong. A person with myopia can see nearby objects clearly, but distant objects appear to be blurred.

2.We are able to taste the food we eat with the help of our tongue. The tongue has a large number of taste buds, which tell us the taste of different types of food items.

3.It is a process by which eye changes it's focal length to form clear image on the retina. As we know, position of image formed by lens changes as object distance changes. Hence, to form the image at the same position it is required to change the focal length of lens. The same thing our eye do. Accommodation is a reflex processes of body. Focal length of eye changes by changing the focal length of eye and focal length changes due to ciliary muscles. Maximum power of human eye is 15 dioptres. An adult human eye can focus objects placed at infinity to as near as 6.5 cm from the eye. The whole processes can occur in as little as 350 millisecond.

Answer 2

(i) Myopia

Commonly known as nearsightedness, it is a condition in which people can see nearby objects clearly; however, the faraway ones appear blurred. This refractive error occurs when the light rays focus at a point in front of the retina, instead of on its surface.

Causes: An eyeball longer than normal.

Affected age: Develop commonly in childhood or teenage years, may get worse with increasing age, though rarely.  

Treatment: This corrected temporarily using corrective lenses and almost permanently by laser eye surgery.

(ii) Taste buds

They are the small sensory organs present throughout on the tongue. They are exactly located in the papillae, which are the small bump-like projections on the tongue.  

Taste buds are responsible for the perception of the tastes – sweet, salty, sour and bitter because they contain numerous taste receptor cells known as ‘gustatory cells’, which are actually responsible for the sensation of taste.

The number of taste buds in an adult tongue ranges between 2000 and 4000.

(iii) Accommodation

It is the ability of the eye to focus far and near objects clearly by adjusting its focal length. This helps the light rays fall correctly on the retina enabling vision.

Ciliary muscles attached to the lens plays the role of changing the shape of lens by altering its curvature via their contraction and relaxation. This process adjusts the focal length.

Also, the constriction of pupils allows maximum light rays to enter the eye rather than getting scattered out.  

Explanation: