“Autosomal Dominant Compelling Helio-Ophthalmic Outburst,” or “ACHOO Syndrome.”
What do I know about this?
Not much. I want to say I’ve heard of it — but I’m sure it was in passing as a “random fact” somewhere. I don’t personally sun sneeze.
What is it?
Sun sneezing, or photic sneeze reflex, is an involuntary sneeze reaction when someone looks at bright lights.
What is surprising?
According to the Wikipedia entry, The condition affects 18–35% of the world’s population
What causes someone to sneeze?
Sneezing is usually triggered by contact with infectious agents or after inhaling irritants pass through the nasal hairs to reach the nasal mucosa.
What is a sneeze?
A sneeze is a semi-autonomous, convulsive expulsion of air from the lungs through the nose and mouth, usually caused by foreign particles irritating the nasal mucosa (membrane). It expels air forcibly from the mouth and nose in an explosive, spasmodic involuntary action resulting chiefly from irritation of the nasal mucous membrane.
Why do we sneeze?
To expel mucus containing foreign particles or irritants and cleanse the nasal cavity. During a sneeze, the passage to the mouth partially closes so that air ejected from the lungs may be expelled through the nose. Because the closing of the mouth is partial, a considerable amount of this air is usually also expelled from the mouth. The force and extent of the expulsion of the air through the nose varies.
Why would someone sneeze when looking at the sun?
Sneezing occurs due to signals sent from the nose via neural pathways to the brain.
Theory One:
Sun sneezing occurs appears to be the result of crossed wires somewhere along the trigeminal nerve, the largest and most complex paired nerve in the head, with three major branches leading to the eyes, nasal cavity, and the jaw.
Bright light causes your pupils to contract, so that signal might be mistakenly sent to the nose as well.
Theory Two:
Sun-related sneezes might occur thanks to ‘parasympathetic generalisation’: a process that occurs when one part of the parasympathetic nervous system — such as the pupil of the eye — is excited by a stimulus and happens to activate other parts of the system as well — such as the membranes in the nose.
Genetic cause:
It is thought to be caused by a dominant X chromosome defect (if either parent is affected, their child has a 50% chance of inheriting the syndrome) however 23andMe researchers have identified at least 54 genetic markers so far.
Facts:
17–35% of the population sun sneezes. This can be experienced as a slight prickling of the nose or a full sneeze. The reflex is constant from episode to episode and typically numbers two or three.
Each sneeze sprays thousands of tiny droplets surprisingly far and fast: they can go farther than two and a half feet, and move at speeds of up to 12 mph.
There is concern ACHOO can be dangerous to drivers and pilots. “ More recently, reports in publications oriented to military medicine have noted the potential danger to pilots experiencing the PSR. In fact, studies conducted by the military revealed that the PSR is not mediated by specific wavelengths of light and thus cannot be mitigated by the use of filtering lenses; rather the investigators concluded that the PSR is induced by changes in light intensity.”
Sources:
https://www.23andme.com/topics/traits/photic-sneeze-reflex/
https://www.ncbi.nlm.nih.gov/pubmed/28520355
https://www.scientificamerican.com/article/why-does-bright-light-cau/
Feedback from Speed Dating
I thought pretty quickly I am going to need to find a metaphor to tie together aspects of sun sneezing. Simply showing a diagram of nerves in the brain isn’t particularly interesting and can look a little gross. I’m going to try to look at other examples because I know human anatomy things like neurons are often described with metaphors to make them more accessible and interesting.
Things that I should explore:
- difference between sun sneezing and regular sneezing — if there is one, such as intensity, duration, etc
- Is it just annoying or why should we care?
Particularly a “why should we care” is difficult because whereas other students have complex, topical, or scientific issues sun sneezing seems like an outlier.
I may try to tie it in with genetic traits or the nervous system maybe more broadly.
I also found it interesting that sun sneezing seems so hard to prevent!
more resources:
10/03
Upon further looking I think it may be beneficial to back up and approach sun sneezing as an entryway to the trigeminal nerve. Without making the presentation about the trigeminal nerve — sun sneezing is about a the nerve. Everyone knows what a sneeze is so that is not interesting. Approaching it as a way to learn a bit about the trigeminal nerve nerve system is maybe more interesting and answers the “why should we care” portion.
Animation Mood Board
https://www.figma.com/file/hbANAIVwjiiKajqkILMOcQ/Untitled?node-id=0%3A1
videos:
https://helloceda.com/portfolio#/autonomy/
https://vimeo.com/289879647
https://vimeo.com/120878175
Sun Sneezing Script
Have you ever heard someone say they’re allergic to the sun?
(sun -> nose _> ::sneeze:: -> kleenex)
For 15–30% of people sudden exposure to light — whether flipping on a bulb in a dark room, or seeing the sun as it emerges from behind clouds — causes a sudden outburst of one or multiple sneezes.
([black] -> Light bulb -> clouds -> sun)
(multiple nose -> ::mutilple sneeze:: -> kleenex)
This phenomenon — known as photic sneeze reflex, or sun-sneezing, is thought to be the result of misfiring in the trigeminal nerve, a cranial nervous system containing three branches;
(::nose connects to face:: -> show full nerve system red = ophthalmic nerve] [blue = maxillary nerve] [yellow = mandibular nerve])
the ophthalmic nerve, responsible for sensory information from the upper part of your face, including your forehead, scalp, and upper eyelids.
The maxillary nerve, which transmits sensory information from the middle part of your face, including your cheeks, upper lip, and nasal cavity,
and the mandibular nerve which sends sensory information from your ears, lower lip, and chin while controlling the movement of muscles within your jaw and ear.
(::branches light as explained::)
During a sneeze caused by irritation of the nasal cavity, the maxillary nerve sends a signal through the trigeminal nerve into the brain forcing the nervous system to expel air from the lungs through the nose and mouth.
(irritant in nasal cavity -> maxillary nerve lights -> sneeze)
Similarly, when an eye that has adjusted to low light is suddenly exposed to brightness, the ophthalmic nerve sends a message instructing the pupil to suddenly constrict so less light enters the retina.
(eye -> light bulb -> ::pupil constricts::)
(nerve system -> ::nerve lights up::)
Because the ophthalmic and maxilliary nerves are so close together, these neurological signals get crossed, resulting in a sun sneeze.
(::show lights get crossed::)
(nose -> ::sneeze:: -> Kleenex)
Feedback:
- Script is very technical but doesn’t tie together the viewer to “care” by being a story
- Include genetic information, and the fact that sun sneezing is not preventable.
I am going to attempt to put at least a beginning and ending with some sort of character flow to tie it together.
Script Two
The Sun is the gravitational center of the solar system. Its pull keeps the planets in their orbits.It warms the earth. It makes plants grow.
(sun -> planet around sun -> plant)
And it makes me sneeze — every time I see the damn thing. Two times — every time.
(face -> ::sneeze:: -> ::sneeze again::)
Nearly one in four have a condition called ACHOO syndrome: autosomal dominant compulsive helio-ophthalmic outbursts — or sun sneezing, an autosomal-dominant trait wherein sudden exposure to light — whether flipping on a bulb in a dark room, or seeing the sun as it emerges from behind clouds — causes a sudden outburst of one or multiple sneezes.
([spell out anagram])
([black] -> Light bulb -> clouds -> sun)
(face -> ::mutilple sneeze:: -> kleenex)
This phenomenon — known as photic sneeze reflex, or sun-sneezing, is thought to be the result of misfiring in the trigeminal nerve, a cranial nervous system containing three branches;
(::nose connects to face:: -> show full nerve system red = ophthalmic nerve] [blue = maxillary nerve] [yellow = mandibular nerve])
the ophthalmic nerve, responsible for sensory information from the upper part of your face, including your forehead, scalp, and upper eyelids.
The maxillary nerve, which transmits sensory information from the middle part of your face, including your cheeks, upper lip, and nasal cavity, and the mandibular nerve which sends sensory information from your ears, lower lip, and chin while controlling the movement of muscles within your jaw and ear.
(::branches light as explained)
During a sneeze caused by irritation of the nasal cavity, the maxillary nerve sends a signal through the trigeminal nerve into the brain forcing the nervous system to expel air from the lungs through the nose and mouth.
(irritant in nasal cavity -> maxillary nerve lights -> sneeze)
Similarly, when an eye that has adjusted to low light is suddenly exposed to brightness, the ophthalmic nerve sends a message instructing the pupil to suddenly constrict so less light enters the retina.
(eye -> light bulb -> ::pupil constricts::)
(nerve system -> ::nerve lights up::)
Because the ophthalmic and maxilliary nerves are so close together, these neurological signals misinterpreted by your trigeminal nerve, resulting in a sneeze.
(::show lights get crossed::)
(nose -> ::sneeze:: -> Kleenex)
Although sneezing is in itself harmless — sneezes are accompanied by momentary loss of vision. Dashing any dreams a sun sneezer like myself might have of being an outdoor tightrope walker.
(tightrope)
Fortunately, ACHOO syndrome is avoidable by wearing sunglasses.
(face -> sunglasses -> ::sunglasses go on face::)
Cool video
