Archive for March, 2015

Night Vision Without the Goggles

March 26, 2015 Leave a comment

The human eye consists of focusing elements and photoreceptors. Images are formed when light is projected onto the retina, which houses photoreceptors called rods and cones. These cells then relay the focused light into our optic nerves

and, subsequently, brains. Typically, cones can only perform optimally with relatively large amounts of light while rods are much more sensitive and perform well in lower light. The strongest images are presented by focusing the light onto the fovea centralis, where the highest concentration of cones is found. Interestingly, the fovea can present a ‘blindspot’ in dim light as rods that account for more peripheral vision can detect low light where cones cannot. Dark adaptation of vision occurs most optimally after 30 minutes.

Science for the Masses, a group based in Tehachapi, CA, may have just found a way to grant humans night vision without goggles. Their work is based heavily on a chlorophyll analog called chlorin e6 (Ce6) a protein typically used as an anticancer drug, an antibacterial, and nanoformulation.

Ce6 has a high molar absorption in the spectral red region and can be easily produced using Chlorella or green plants. For these reasons, it has garnered much attention as a photosensitizer. In human medical treatment as an anticancer drug, Ce6 is used for its ability to amplify light from low power light sources. This allows a medical team to target cancer cells with precision. The reaction that Ce6 undergoes produces harmful oxygen species that kill the tumor cells. It has also been demonstrated to be effective as an antibacterial.

This ability to increase photosensitivity has promoted notions of creating a treatment for nightblindness. Taking notes from a patent that discusses this very idea, Jeffrey Tibbetts and Gabriel Licina have been able to show increased vision in low light situations when administered to an individual with healthy eyesight.

Using the mixture of Ce6, saline and insulin found in the patent, Licina was dosed 3 times with 50uL in each eye. Sunglasses and dark sclera lenses were used after dosing to ensure low light conditions and reduce the potential for damage due to light exposure. Licina made up the only test subject; 4 other individuals constituted the control group.

At 10 meters, Licina could identify different both static symbols and moving symbols against different backgrounds, At 50 meters, Licina could detect individuals standing among trees in the woods with 100% accuracy, as compared to a control group not dosed with Ce6 who had about 30% accuracy. The effects seem to wear off by the next day.

While this treatment certainly seems to open doors, it should be noted that much more extensive research is required. While no damage has been noted by the authors, a much larger sample size is required for safely administering this drug. Exact measurements to test the true extent of enhancement would also help in evaluating this treatment’s efficacy. On a cellular level, how does this chemical affect our rod and cone populations? Could it extend our sight farther down into the red? At what level of darkness does detail begin to fade?

The future is almost here!

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