The perception of the world that our brain assembles from sensory information is limited in scope and, as a certain dress demonstrated a week ago, not terribly accurate. That doesn't diminish the richness of what we do perceive. After all, we often find enormous beauty in black and white photography and low quality sound reproduction. But what if some of our senses could be extended - even just a bit...? I have a few posts about playing with a sense.1
Light comes in a wide range of wavelengths and we are sensitive to a range between about 400 and 700 nanometers - what is often called visible light. Most of us have three varieties of color receptors. These cones are sensitive to overlapping ranges of frequencies and send signals to our brain where we assemble a color image.2 Our brains allow us to perceive roughly a million colors. Very roughly and there is great variation. Women have a better color discrimination than men - particularly among the reds. Additional types of cones would vastly improve color discrimination. Tetrachromacy is common among birds and there is some indication that a few humans have it. But for most of us the best we can hope for is to be female.
There may be some hope for extending your vision into the near ultraviolet. It has been assumed that vision extending into the ultraviolet is rare among mammals. The culprit is the optical train - mostly the lens. A new study published in the Proceedings of the Royal Society B shows a great degree of variation in transparency of the ocular media among mammalian species.3 There are mammals that should have vision extending well into the ultraviolet.
This brings us to a hack. Many of us will need cataract surgery at some point in our lives. The prosthetics used are mostly UV opaque, but apparently some are partially transparent. If you can arrange to get one that is transparent the world you see may be different. Have a chat with your eye surgeon when the day comes...
It is unusual to think of a surgery associated with age that leaves you with an enhanced ability. Down the road it is likely we'll be able to use implanted sensors giving augmented views of the world, but in the near term some of us may be able to directly experience a new world.
1 a few hacks from earlier posts
° The rods and cones in your retina have vasty difference sensitivities and different recovery times from being saturated. It is possible to find color in dim light sources.
° Speculation on bat audio and dog vision.
2 Although wavelengths are often labeled with colors like 620nm red, 425nm blue, that isn't accurate. Although we can label visible light frequency with color labels not all colors are represented by single wavelengths. Pink, for example, is a combination of red and blue wavelengths.
3 The paper is currently outside their paywall.
The spectral transmission of ocular media suggests ultraviolet sensitivity is widespread among mammals
R. H. Douglas1 and G. Jeffery2
1Department of Optometry and Visual Science, City University London, Northampton Square, London EC1V 0HB, UK
2Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK
￼ Although ultraviolet (UV) sensitivity is widespread among animals it is considered rare in mammals, being restricted to the few species that have a visual pigment maximally sensitive (lmax) below 400 nm. However, even animals without such a pigment will be UV-sensitive if they have ocular media that transmit these wavelengths, as all visual pigments absorb significant amounts of UV if the energy level is sufficient. Although it is known that lenses of diurnal sciurid rodents, tree shrews and primates prevent UV from reaching the retina, the degree of UV transmission by ocular media of most other mammals without a visual pigment with lmax in the UV is unknown. We examined lenses of 38 mammalian species from 25 families in nine orders and observed large diversity in the degree of short-wavelength transmission. All species whose lenses removed short wavelengths had retinae specialized for high spatial resolution and relatively high cone numbers, suggesting that UV removal is primarily linked to increased acuity. Other mammals, however, such as hedgehogs, dogs, cats, ferrets and okapis had lenses transmitting significant amounts of UVA (315–400nm), suggesting that they will be UV-sensitive even without a specific UV visual pigment.
A recent purchase of Korean sweet potato noodles has led to some experimentation. Here is a noodle dish that worked out well. You can find the noodles in an Asia food store or on Amazon. This is a modified recipe using what was on hand and no fish sauce. Lots of variations - do what seems interesting.
Sweet potato noodles with vegetables
° about 8 ounces of dried Korean sweet potato noodles
° vegetable oil (about 2 tbl)
° about 8 shiitake mushrooms cut into thin shreds
° one medium white onion ° about 8 shiitake mushrooms cut into thin shreds
° one green pepper ° about 8 shiitake mushrooms cut into thin shreds
° one clove finely minced garlic
° 1/2 cup vegetable stock
° some sesame oil (about 3 tbl)
° soy sauce (2 or 3 tbl)
° 1 tbl white sugar
° Bring a pot of salted water to a boil over a high heat. Add the noodles and cook until transparent and al dente. Maybe four or five minutes. Halt the cooking by dumping the noodles into a bowl of ice water. Drain and set aside.
° Heat the veg oil in a wok over medium high heat. Add the veggies, salt and pepper and stir fry until soft. Add the garlic and continue until it smells great.
° Add the noodles and the other ingredients and stir fry until the liquids are mostly absorbed - about three minutes.