Vision visionaries
In this Trailblazers podcast excerpt , host Walter Isaacson explores the work of vision pioneers from the past .
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In 1992 , young doctor Mark Humayun attempted groundbreaking surgery on a blind patient . His idea was revolutionary : If he used electrodes to stimulate the retina and it relayed those signals to the brain , would the brain detect them as light ?
The retina is crucial to our vision . This extension of the optic nerve has hundreds of millions of photoreceptors called rods and cones that convert light into electrical signals for the brain . Unlike skin , they don ’ t regenerate . The photoreceptors decay with age and disease , as does our vision .
In an operating theater at the Duke [ University ] Eye Center in Durham , North Carolina , Humayun implanted the electrodes with a tiny surgical incision . At first , the patient saw nothing . Then — success . He reported the first dim light he had seen in half a century . This use of electrodes to stimulate the optic nerve heralded a new era of innovation in eye treatment .
LOOKING FURTHER BACK Scientists throughout history have focused on understanding the retina , but beginning in the 1970s , Dr . Patricia Bath looked beyond what was inside the eye . What she saw changed ophthalmology forever .
Bath co-founded the American Institute for the Prevention of Blindness and became the first female faculty member at the UCLA Stein Eye Institute . During her internship , split between Harlem Hospital and Columbia University , she had found a worrying disparity : Blindness among Black patients was more than double that of white patients .
The causes were social and economic ; the two communities had unequal access to eye care . She responded by inventing community ophthalmology . We can thank her for eye tests in public schools and screening of seniors for eye disease .
This was just one of Bath ’ s achievements . In the 1980s , she focused on cataracts , a clouding of the lens of the eye , common in older patients .
“ Cataracts are the most common cause of reversible blindness ,” explains Dr . Lisa Nijm , a board-certified ophthalmologist and the CEO of Women in Ophthalmology . She explains that cataract surgery reduces hip fractures in older patients by 60 %. “ I think Dr . Bath focused on cataracts because it underscores the critical