The Harvest Moon

Blog vol 3. 21. The Harvest Moon.


On October 9th, we enjoyed the full moon that is traditionally called the “Harvest” moon. It occurs around the Autumnal Equinox, so either in September or October, and it happens at harvest time in the northern hemisphere.


What I marvel at is the size of the harvest moon; it appears twice as large when it starts to come up over the horizon. Sorry to burst your bubble or remove a little magic from your lives, but it really is no bigger, it just looks that way.


Scientists have scratched their heads on this one. 



There is the long-known Ponzo illusion, where we have converging perspective lines and two horizontal lines above each other, the one further back looks longer even though they are actually the same length.

This goes a long way to explaining our larger moon. When the moon is near the horizon, our brain perceives it as closer to us and adjusts the perceived size. There are many ways to tell that this is happening. One way is to take a picture of the moon on the horizon and then with the same settings take a shot of it up in the sky, and you will find that the moon is the same size. Another way, which is less technical, is to just turn around and bend over and peek between your legs, upside down, and a smaller moon ensues.  


What is really cool, is that astronauts out in space still experience this same moon illusion, even though there are no background clues to help make it happen. (Read more about this moon illusion here). My best guess is that we have learned perspective patterns that just kick in whatever the circumstances.


The Harvest moon is also named for its time of rising.  Usually, there is a ½ hour difference from day to day on the time of moonrise, but the Harvest moon rises at about the same time every evening. It gives the perception that we have more days of full moon at this time of year to help in the harvesting. 


The reason for this timing is the angle from the elliptic, which is the path that the planets and the moon follow as we track them in the night sky. During September and October, we have a shallower angle in the east for this path resulting in less variation in the time of moonrise.   


All this to say that it is a great time of year to go out and enjoy a moon on full display.  



Til next week,



the good doctor


By Dr. Mark Germain May 1, 2026
The good doctor discusses how the eye is a window to the heart with the help of the OCT.
The good doctor take a deeper look at how gut health is connected to eye tissues.
By Dr. Mark Germain April 29, 2026
Blog vol 6.40. The Gut and the Eyes. One of my biggest jobs is to keep abreast of new research and advances in eye health. Most recently, we have seen new stem cell research, gene therapies, as well as new drugs for dry and wet macular degeneration. In January of this year, there was an article in the journal, Cell Death and Disease, that looked at cell apoptosis, specifically with the photoreceptors of the eye. (Read the article here ). Apoptosis is the genetic programming of deliberate and constructive cell death, allowing for the maintenance of healthy structures and systems in the body. Some estimates have the body replacing 50 to 70 billion cells daily by this process. Necrosis, on the other hand, is unplanned cell death caused by injury, toxins, or other negative outside factors; this causes inflammation and disrupts the body’s balance of things. There are stressors that speed up cell turnover. The study looked at photoreceptors in the retina and were able to demonstrate cellular recovery, even in late stages of apoptosis, recovery not breakdown. When certain stressors were reduced, by working with the mitochondria, there was recovery of the photoreceptor cells. How? Mitophagy, the mitochondria’s own process of programmed breaking down and then repurposing the recycled components for new ones. This mitochondrial repair helps to reverse the sequence of apoptosis for the photoreceptors. Mitochondria, how cool. How is this helpful for our eyes? Conditions like retinitis pigmentosa or macular degeneration directly involve the photoreceptors and may be slowed or reversed by helping the mitochondria. So, let’s take care of those mitochondria. There is some evidence for nutritional support for the mitochondrial system. The nutrient, Urolithin A (UA), which is a compound made in our gut from fiber found in pomegranates, berries, and nuts is the only clinically proven substance known to trigger mitophagy, made in the gut no less. Vitamin B3 is critical for mitochondria function, however vitamin B3 based supplements are still to be clinically tested for their support of cell recovery. Nutrients Coenzyme Q10 and L-carnitine are known to help the mitochondria generate energy, and interestingly, infrared light therapy has also been shown to benefit mitochondrial function. Again, food for thought. The gut and its function needs a lot of research. How do probiotics and nutrient precursors affect eye tissues? It is so interesting that the gut can be a factor in eye health. Maybe adding Urolithin A as a supplement is wise, along with the antioxidants in Lutein and Zeaxanthin we use to combat photoreceptor degeneration. Will keep you posted on any new developments.  The good doctor
By Dr. Mark Germain April 16, 2026
The good doctor focuses in on visual processing. Why do we miss things that are right in front of our eyes?
By Dr. Mark Germain April 10, 2026
The good doctor discusses the Artemis II mission, space travels affects on the eyes, and "the dark side of the moon"
By Dr. Mark Germain April 3, 2026
The good doctor discusses exciting new and emerging options to treat nystagmus.
By Dr. Mark Germain March 27, 2026
The good doctor reflects on The Country of the Blind, a book by Andrew Leland which gives insight into the experience of vision loss.
More Posts