im not sure. probably... far sided.
both
concave :)
Farsighted people use convex lenses to correct their vision.(This is the correct answer!)
A concave lens helps you see far if you're nearsighted and convex lenses help you see near if you're farsighted.
Concave lenses are used in glasses for people who are near-sighted. Convex lenses are used in glasses for people who are far-sighted.
The ocular lens used for nearsightedness is known as a diverging lens. It is also known as a concave lens.
Using concave lens the short sight problem could be rectified. Near sighted person cannot see the things far away. He can see things only so near to his eyes. The ray coming from the far object would form an image just before retina since the eye ball is elongated horizontally. So to make the image to move backward and fall on the retina, a concave lens is used to diverge the ray and finally the image would fall on the retina. Thus the remedy is possible with concave lens.
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.
Lenses can correct vision problems by bending light rays before they reach the eye, in effect moving the focal point of the eye's lens so that it falls upon the retina and creates a clear image. Concave lenses cause light rays to converge and lengthen the focal point for the near sighted eye. Concave lenses are thinner in the middle and thicker on the edges and may be curved on one or both sides. Concave lenses cause light rays to diverge, or spread apart. :)
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
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
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 -
No, think about it, if you are near sighted you can see near, if you are far sighted you can see far, if you are both you can see both No, think about it, if you are near sighted you can see near, if you are far sighted you can see far, if you are both you can see both
Both give diminished, virtual, erect image. Hence convex mirror is used as rear view glass in case of vehicles near by the drivers. Concave lens is used to correct short sightedness.