Functional Human Eye

This Functiol Human Eye Model of the Human Eye demonstrates the way the lens thickens or flattens to focus an image on the reti. The actual lens is a chamber constructed of optically clear silicone elastomer connected by tubing to a water-filled syringe. Water forced into the lens increases its thickness and curvature; withdrawal flattens the profile of the lens, changing its focus. The " Shape" of the eye can also be altered to simulate myopia (nearsightedness) and hypermetropia (farsightedness) . Used in conjunction with a bright light source (such as an ordiry slide projector), images can be focused on the model's reti. You can dramatically demonstrate visual accommodation; near-point of vision; visual blind spot; presbyopia (age-related loss of accommodation from lack of lens elasticity) ; and the use of corrective lenses to treat myopia and hypermetropia (lenses and lens holder included) . Complete with illustrated instructions and projection object on stand with numbered Key Card.