What Is Photodynamic Therapy?

Photodynamic therapy is designed to eradicate diseased cells. Specific substances found within tumors can absorb designated wavelengths of light. When these substances are illuminated properly, they release a form of oxygen that can harm nearby cells and tissues. In essence, PDT utilizes targeted light exposure to eliminate unwanted cells.

The Enigma of Human Vision

Human vision relies on photoreceptor cells located in the retina. These cells transmit visual information to other nerve cells, which in turn relay it to the brain for interpretation. There are two primary types: rods and cones. Rods facilitate night vision, whereas cones enable color perception during daylight hours. When individuals experience vision issues or blindness, it's often due to problems with these cells.

Various animals possess different visual capabilities compared to humans. For instance, dogs excel in low-light conditions, while birds of prey have superior vision throughout the day. One major reason humans struggle to see in dim light is due to the retina's light sensitivity. When exposed to excessive light, certain retinal cells cease functioning, a process known as apoptosis. Additionally, humans have difficulty perceiving infrared light.

How PDT Enhances Night Vision

Recent findings reveal that the photosensitive pigment chlorin e6 binds with rhodopsin, a light-sensitive protein in our eyes. This compound typically doesn't allow us to detect infrared light. At night, our eyes receive minimal light input, making visibility challenging. During daylight, retinal components detach from rhodopsin, creating signals sent to the brain that inform us of our surroundings.

By combining infrared light with a chlorin e6 injection, a similar effect to that of visible light can be achieved in our eyes. This means improved visibility in darkness. As chemist Antonio Monar states, “This explains the increase in night-time visual acuity.”

Experiencing Enhanced Night Vision

Patients undergoing photodynamic therapy have reported perceiving unusual shapes, patterns, and silhouettes in low-light environments. Individuals receiving this treatment for cancer often feel that their night vision improves during the therapy, although this effect seems temporary and diminishes after treatment ends.

The Future of Vision Enhancement

This discovery opens exciting possibilities for the future of vision. Medical professionals are optimistic that further exploration of this phenomenon could provide new treatment avenues for those suffering from blindness or light sensitivity. Additionally, there may be military applications, allowing soldiers to operate effectively in low-light conditions.

Final Thoughts

The understanding of this effect is still in its early stages, and researchers are actively learning about its implications. It may take years to fully comprehend the potential of PDT as a means to enhance human vision. Health professionals advise against experimenting with chlorin e6 without proper guidance.

Sources

• ScienceAlert: There’s a Cancer Treatment That Gives People 'Night Vision’. Here’s How
• BigThink.com
• Cancer.org