what is astigmation and how is it caused?
also why the path of light becomes visible when milk is added to it
Asked by Shagun Rastogi | 14th Mar, 2015, 07:13: PM
Astigmatism is the inability of the eye in focussing objects in horizontal or vertical lines clearly.
i.e. inability to focus all lines of an object in one plane in a single image plane.
This defect arises because the cornea does not have a spherical shape, it curves more in one direction than in another.
Astigmatism is an eye condition with blurred vision as its main symptom.
This defect can be corrected by using cylindrical lenses, so that the convergence produced by the eye lens and the cylindrical lens together will be the same.
If a beam of light is passed through a milk solution, the path of light becomes visible because in milk solution the particles are large enough to scatter the beam of light. This scattered light enters our eyes.
Answered by Jyothi Nair | 16th Mar, 2015, 11:04: AM
- what's myopia
- why normal can see only 25cm
- Where is the structure for bifocal lens
- Gently handle the spectacles of your grandparents and check the type of curvature in the lenses and record the observations about the vision through these lenses
- A person is unable to see distinctly the objects placed beyond 6m.Name the defect of vision he is suffering from?
- When a person is suffering from both myopia and hypermetropia, then what type of correction lenses are required?
- What is Presbyopia? How can it be corrected?
- State two main causes of person developing near sightedness. How can this defect be corrected?
- Give three differences between myopia and hypermetropia.
- The far point of a myopic person is 150 cm in front of the eye. Calculate the focal length and the power of lens required to enable him to see the distant objects clearly.
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