(5 Points) You are designing eyeglasses for someone whose near point is 65 cm. What focal...
The near point of an eye is 100 cm. A corrective lens is to be used to allow this eye to clearly focus on objects 26.0 cm in front of it. (a) What should be the focal length of the lens? (b) What is the power of the needed corrective lens?
The near point of an eye is 111 cm. A corrective lens is to be used to allow this eye to focus clearly on objects 25.0 cm in front of it. What should be the focal length of this lens? What is the power of the needed corrective lens (in diopters)? Do not enter units.
For a normal eye, the near point is 25.0 cm. This is where you would like to place the printed material such as the newspaper to read. The far point is very far away. What type and focal length corrective contact lens should a nearsighted person whose far point is 80.0 cm wear? What is the power of this lens? What type and focal length corrective contact lens should a farsighted person wear if the persons near point is 60.0...
A person is nearsighted with a near point of 75. cm. (a) What FOCAL LENGTH is this? (b) What POWER lens is needed to correct their nearsightedness (assuming distance from lens to eye is negligible)?
A physicist can see distant things clearly when wearing -2.00-diopter eyeglasses. Each lens rests 1.55 cm in front of the eye. (a) What focal length (in cm) describes the lenses? (b) Determine the far point (in cm) for this physicist's eyes. (c) is the physicist nearsighted or farsighted? nearsighted farsighted (d) The physicist decides to replace eyeglasses with contact lenses, one of which rests directly on each eye. What would the contact lens power be (in diopters) in order to...
Reading glasses of what power are needed for a person whose near point is 50.0 cm, so that she can read clearly the print of a book located at 25.0 cm? Assume a lens-eye distance of 2.00 cm.
An object is placed 15 cm in front of a divergent lens whose focal length is 12 cm. Where would the image be located (in cm)?
A 5 cm tall object stands in front of a converging lens with focal length f = 35 cm. The distance between the object and the lens is 10 cm. (a) Give the power of the lens. (b) Calculate the position and height of the image formed. Is the image real or virtual? (c) In the space below clearly produce the ray diagram (at least two of the three rays that form the image). A farsighted person uses spectacles formed...
Part II: Corrective Eyeglasses Not everybody can adjust their eyes to be able to see both distant and nearby objects clearly. In a normal eye, light from a distant object forms a sharp image on the retina. In a far-sighted eye, light from a distant object converges too gradually and would form a sharp image behind the retina (of course the retina gets in the way, and thus a blurry image hits the retina). In a near-sighted eye light from...
Given: Assume the near point (of the eye) is 25 cm . The distance between eyepiece and objective lens in a certain compound microscope is l = 17.6 cm . The focal length of the eyepiece is fe = 2.57 cm , and that of the objective lens is fo = 0.3 cm . What is the overall magnification of the microscope? Caution: a negative quantity this is. Use the approximation l − fe ≈ l and object distance do...