You are trying to focus your camera so as to get a picture of a near and a far object. You can focus the camera by moving the lens but you cannot change your position nor can you move the objects. That is, you can move (click-drag in the simulation) the lens in front of the film. How far does the lens have to move in order to change the focus between the two objects? All distances are measured in mm. Start
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The human eye accommodates for near and far objects by changing its focal length. The simulation shows the lens, outlined in red, and the retina, drawn in yellow, of an eye that is trying to accommodate by contracting its ciliary muscles. The effect of the cornea has been included in the lens. What is the near point for this eye? Distance is displayed in mm. Start.
The human eye accommodates for near and far objects by changing its focal length. The simulation shows the lens and the retina of an eye that is trying to accommodate by relaxing its ciliary muscles so as to focus on a far object. (The effect of the cornea has been included in the lens.) Distance is displayed in mm. What is the far point for this eye? Start.
The above animation models an eye. The retina is the yellow line on the right. The eye's lens and the cornea have been modeled by a single lens. Click-drag either the point source or the beam from behind the retina to the front of the lens. That is, drag a source from the right hand side of the animation to the left hand side. From your observations, is the eye nearsighted or farsighted? Start
The above animation models a farsighted eye with relaxed ciliary muscles. The eye's lens and the cornea have been modeled by a single lens which has been outlined in red. Can this person's vision be improved with glasses? Click-drag either the point source or the beam from behind the retina to the left side of the screen in order to decide on a prescription. The retina is the yellow line on the right. Distance is measured in mm. Start
A movable object is viewed without a magnifying lens and with a magnifying lens. What magnification does the lens provide? The retina is the yellow line on the right hand side. Angles can be measured by click-dragging inside the animation. Distance is measured in mm. Start.
Two lenses are used to make a Keplerian telescope. What is the magnification of this telescope? You may click-drag the light beam to any position. Start
Two lenses, an eyepiece and an objective, are used to make a microscope. Where should the object be placed for optimal viewing by a relaxed eye. You may focus the microscope by click-dragging the object into position. Position is measured in cm. Start
Drag either the blue or the red point source and observe the aberration of the focus. Which of the following statements is true? Start
