Natural selection is about the survival of the fittest, but it is not perfect. How can we fix it?
Episode 1
"The Eye Of The Beholder"
Synopsis
The human retina is upside down: the photoreceptor cell layer, which converts light into electrical signals, is in the back of the retina, while the cells that send these electrical signals to the brain are in front of them (closer to where the light is coming from)
Light penetrates the retina, goes all the way to the back where the photoreceptors are, and triggers an electrical signal that has to travel backwards towards the front of the retina.
How and why did evolution come to this weird design?
How are modern optical tools designed differently from the retina?
If we could engineer a human eye to be perfect, how would we do that?
The episode shows how the evolutionary design of the eye and the retina leads to visual limitations (field of view, contrast resolution, color perception, etc.)
Also, this upside-down design of the retina makes it hard for doctors to treat a myriad of diseases that affect our vision.
How do we cope with these diseases today, and what are the strategies of the future?
The episode features prominent scientists from around the world (see specific names in the minute-by-minute development-chapter at the end of the presentation) working on methods to restore vision in blind people.
There are 3 main methods:
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To insert in the blind retina a small chip that can react to light and create electrical signals (just like our natural photoreceptor cells, that have died in the blind person);
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To add chemicals [opto-pharmacology] or genes [opto-genetics] that create a response to light in the cells that are still alive;
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To recreate the dead parts of the retina by introducing stem cells and regenerative therapy.
In the future, there could be even a fourth approach: to create a completely artificial eye, that would not only restore vision to the blind, but will be even better than the normal healthy human eye.
For example, can we design human eyes that can see infrared and ultraviolet light-waves, that have a much wider vision field and can see in the dark?