If you are near sighted u can see close but not at distances so you would have to use a negative lense in glasses or contacts such as -1.25
A far-sighted person should use convex lenses. These lenses help to converge the incoming light rays so that they focus correctly on the retina, correcting the vision for far-sightedness.
A convex or converging lens can fix eyes with long sighted vision. A person who is long sighted cannot focus on near objects which can be corrected by wearing a convex lens.ÊÊ
A person who is farsighted needs a converging lens, which is a convex lens, to help focus light properly onto the retina. This type of lens helps to converge incoming light rays so that distant objects can be seen more clearly.
Short sighted people are not helped by lenses or anything else. Except the consequences of their short sightedness. I think you mean near sighted people. The eye is a lens and focal point system. The focal length of the eye can be manipulated by flexing muscles in the eye socket to change the distance between the lens and the back of the eyeball. A near sighted, or even a far sighted, person has an eyeball that is too long or too short for the lens, and therefore the image produced by the eye's lens is focused either in front of or behind the back of the eye. A lens, either in a pair of glasses or a contact lens, can assist the eye by effectively pre-focusing the image that enters the lens of the eye to a sharpness that can be accommodated by the focal length of the malformed eyeball, focusing the image sharply on the back of the eyeball. - wjs1632 -
convex lenses are for short sighted people.
A concave lens is thinner at the centre. People who are short sighted often use a concave lens to help them see better.
The person is moderately myopic (short sighted or near sighted). The person can see things that are closer clearly but things that are far will be out of focus. The eye is bulged and the image forms in front of the retina and a concave lens with -5 power will help in forming a clearer image on the retina.
A long-sighted eye has a lens of insufficient power so that it needs an extra convex (magnifying) lens to bring objects into focus. A more powerful lens allows objects to be focussed at a closer distance, and that is what a magnifying glass does.
Short Contact Lencesnear sight is hyopia
im not sure. probably... far sided.
Image formed by a concave lens or a diverging lens is virtual,upright and smaller than the object.It is used by short sighted people.
If a lens cannot change its shape to focus light, it will not be able to converge or diverge light rays properly to create a clear image. This would result in a blurred or distorted image being formed. The lens relies on its ability to change shape (accommodate) in order to precisely focus light onto a specific point.