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Weltur and the eyes of grandpa

June 11, 2013
Dr. Shahar Madjar - Urologist at Bell Hospital , The Mining Journal

People who die young leave fewer memories behind. My grandfather left this world before I was born - his life, to me, is a puzzle with many missing pieces. Of all the belongings my grandfather once had, only one has remained in my possession. It is a German-made, folding Weltur camera that uses film and can capture black and white images.

I look at the Weltur and I am reminded of the lessons I once learned in a Biology class: "the human eye works like a camera." The similarities were clear. Both the eye and the camera are enclosed, light-tight compartments with a lens mounted on one end and an image sensor at the other. Like the lens of a camera, the cornea (the outer, transparent part of the eye) and the lens of the eye bend rays of light so that an inverted and upside-down image is formed on a film, or on the retina of the eye. And both have mechanisms to control the amount of light that enters the compartment (the diaphragm of a camera, the pupil of the eye).

But the similarities between a camera and the human eye end there. In a camera, for example, focusing on the object of interest is achieved by changing the distance between the lens and the film. In the eye, the distance between the lens and the retina is constant (less than an inch), and focusing is dependent upon the properties of the lens itself (made of rubbery, jelly-like material) and small muscles (called ciliary muscles) around the lens that can make it either more spherical or flatter.

Article Photos

Shahar Madjar, M.D.

Technology is catching up, but it is just beginning its journey to become the marvel that the human eye is. Our eyes are not my grandfather's Weltur, nor are they the most advanced iPhone camera. They provide sharp, vivid, full of contrast, three dimensional images. They are mounted on a bipod (our legs) with many degrees of freedom of movement.

They can move in their sockets, searching for relevant information. They have automatic focusing and light adjustment, and a mechanism for self-cleaning (eyelids and tears). They come fully installed. There is no need for online shopping. Shipping and handling fees are waived. They come for free.

But the main difference between a camera and the human eye is that the eye is only a part, the frontier extension of a much larger system - our brain. The light that enters our eyes forms an image on the retina at the back of the eye.

It is in the retina with its many layers of cells (called cones and rods) where light is translated into small electrical currents, into nerve signals. The signals are then delivered to the visual cortex of our brain, where information is not just recorded but also being analyzed: what is important is retained, what is redundant is ignored, and meaning is king.

In the unlikely event that I will become a film director, the following is a scene in a movie I would like to make. The year is 2052. Thanks to the development of advanced time-machines, my grandfather and I can not only meet, but we can meet as persons of the same age, my age. Each of us, though, is holding a camera of his own generation: an iPhone for me and a Weltur for the grandpa I have never met before.

We are talking and laughing. We are taking pictures, each of us using his own camera. We see each other and all that surrounds us, with the best of all cameras, the only camera that can see, our eyes.

Editor's note: Dr. Shahar Madjar is a urologist at Bell Hospital in Ishpeming. Read and comment on prior columns by Dr. Madjar at DrMadjar.com.

 
 

 

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