User's Manual
®
3
Use with the Human Eye Model
Set the Basic Optics Light Source about 5 to 10 cm in front of
the Human Eye Model with the “crossed-arrow” target
aligned with the opening in the front of the model. Place the
retina viewing screen in the “NORMAL” groove.
Make sure that the lens is filled with a fluid such as water.
Place the Adjustable Focal Length Lens inside the Human
Eye Model in the lens holder groove labeled “SEPTUM” (see
Figure 3).
Push the piston into the syringe to increase the amount of
fluid inside the lens housing and change the curvature of the
flexible membranes.
Observe the image of the crossed-arrow target on the retina
viewing screen.
CAUTION: Do not push the piston too hard because the
membrane may come loose.
Use with Basic Optics Components.
Mount the Basic Optics Viewing Screen near the middle
of the Basic Optics Bench. Adjust the two lower fingers
of the Adjustable Lens Holder to the “35” millimeter
mark. Make sure that the lens is filled with a fluid such
as water. Place the Adjustable Focal Length Lens onto
the grooves at the ends of the two lower fingers and then
adjust the third finger so it holds the lens in place (see
Figure 4).
Mount the Basic Optics Light Source near the end of the
bench. Mount the Adjustable Lens Holder near the light
source
Push the piston into the syringe to increase the pressure
inside the lens housing and change the curvature of the
flexible membranes. Adjust the position of the lens
holder and viewing screen so the image of the target is in
focus on the viewing screen.
Observe the image of the crossed-arrow target on the Basic Optics Viewing Screen. Use the syringe to adjust the curvature of the
lens membranes and observe the change in the image.
Suggestion
Use the Adjustable Focal Length Lens with the Human Eye Model, but fill the lens with air and fill the eye model with water. Make
the level of the water in the eye model high enough to cover the Adjustable Focal Length Lens. Use the setup to explore the behav-
ior of light through a “negative” lens.
Figure 3
Human Eye Model
Basic Optics
Light Source
Adjustable
Focal Length
Lens
Retina Viewing
Screen
Figure 4
Viewing
Screen
Lens
Holder
Light
Source
Optics
Bench