The principal rays emanating from an object are drawn. You can click-drag the tip of the arrow-shaped object inside the pink box (the position is given in centimeters and the angle is given in degrees). A red curtain covers part of the animation and therefore you cannot see the rays in that region. What kind of lens is covered by the curtain? Start
A light source is located to the left of a lens. You can click-drag the lens to any position (the position is given in meters and the angle is given in degrees). Find the focal length of the lens. Start
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An arrow shaped object is located to the left of a lens. The animation is drawn assuming a thin lens and the small angle approximation. You can drag this point object to any position (the position is given in meters and the angle is given in degrees). Find the focal length of the lens. Start
You are trying to focus your camera so as to get a picture of a near and a far object. The animation is drawn assuming a thin lens and the small angle approximation. 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 (the position is given in millimeters and the angle is given in degrees). How far does the lens have to move in order to change the focus between the two objects? Start
Drag either the blue or the red point source and observe the aberration of the focus (the position is given in centimeters and the angle is given in degrees). Which of the following statements is true? Start
The human eye accommodates for near and far objects by changing its focal length. The animation is drawn assuming a thin lens and the small angle approximation. 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 position is given in millimeters and the angle is given in degrees). The effect of the cornea has been included in the lens. What is the near point for this eye? Start.
The human eye accommodates for near and far objects by changing its focal length. The animation is drawn assuming a thin lens and the small angle approximation. 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 position is given in milliimeters and the angle is given in degrees). The effect of the cornea has been included in the lens. 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 animation is drawn assuming a thin lens and the small angle approximation. 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 (the position is given in milliimeters and the angle is given in degrees). 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 animation is drawn assuming a thin lens and the small angle approximation. The eye's lens and the cornea have been modeled by a single lens which has been outlined in red. 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 position is given in millimeters and the angle is given in degrees). The retina is the yellow line on the right. Can this person's vision be improved with glasses? Start
A movable object is viewed without a magnifying lens and with a magnifying lens. The animation is drawn assuming a thin lens and the small angle approximation. The retina is the yellow line on the right hand side. Angles can be measured by click-dragging inside the animation (the position is given in millimeters and the angle is given in degrees). What magnification does the lens provide? Start.
Two lenses are used to make a Keplerian telescope. The animation is drawn assuming a thin lens and the small angle approximation. You may click-drag the light beam to any position (the position is given in centimeters and the angle is given in degrees). What is the magnification of this telescope? Start
Two lenses, an eyepiece and an objective, are used to make a microscope. The animation is drawn assuming a thin lens and the small angle approximation. You may focus the microscope by click-dragging the object into position (the position is given in centimeters and the angle is given in degrees). Where should the object be placed for optimal viewing by a relaxed eye. Start
