Pictures on the Wall

A family member had an appointment with an opthalmologist, and so it was that we were at the Stanford eye clinic, three miles east of the university's main campus.

Rather than look at my phone I prowled the halls and gazed at the collection of '60's pop art. There were Andy Warhols and Roy Lichtensteins (pictured above) on both floors, along with less well-known artists like Allen Jones, Mel Ramos, and Guy Dill.

The screens will always be there, and when you're in a new place, even as nondescript as a doctor's office, you can be pleasantly surprised by getting up and looking around.

“The eyes are truly the window to our souls”

Maybe her eyes can tell us what she's thinking

The nature of consciousness has long been a fundamental question of human existence, and it's no surprise that scientists are employing scientific methods to improve our understanding of the subject.

For example, human beings are not "conscious" when they are asleep, so one criterion of consciousness is that a person must be aware of objects in the person's surroundings: [bold added]

[Researchers] used a combination of artificial intelligence, mathematics, and a close examination of the eye movements of individuals as they were shown images of people’s faces.

As it turns out, they found that important clues are revealed in the eyes. When people were shown clear images, their eye movements showed a distinct pattern that indicates they were aware of their surroundings. However, as the subjects were presented with progressively dimmer images of faces, the pattern of eye movement changed. Tracking these changes, [Yale Prof. Hal] Blumenfeld said, allowed researchers to discern whether the subjects actually perceived the face or not without asking them.

“The eyes are truly the window to our souls,” he said. “We can tell if people are aware of something by simply looking at their eyes.”

The eye-tracking tool allowed researchers to explore the amorphous dividing line between consciousness and unconsciousness, a state most obvious as we awake from sleep. People become progressively more aware of their surroundings as slumber recedes, a process that is controlled in a region of the brain known as the thalamus.

Ultrasound waves directed at the
thalamus can "jump start" coma
patients (Medindia)

The Yale researchers found that when people awake the thalamus discharges a brief pulse which jumpstarts the transition to consciousness. However, this activity is only a first step in a series of actions throughout the brain that leads to full awareness, they found. For instance, that initial pulse from the thalamus may fail to activate other neural networks, keeping the individual unconscious of most surrounding stimuli. However, the pulse can also activate neurons involved in processing visual cues in the frontal cortex, which in turn amplifies circuits involved in arousal and attention. At the same time, signals irrelevant to the event are turned off.

To those of us who have friends or relatives who regularly experience visual and/or auditory hallucinations, the research into consciousness and awareness can't proceed fast enough.

But for those like your humble blogger, whose brain is healthily grounded in reality (!) and is concerned about scientists being able to read thoughts through eye movements, wearing sunglasses is strongly recommended.

The Meanness of an Urban Setting

The office is a mile from downtown San Jose.

My opthalmologist whom I liked very much, retired a few years ago, and the doctor who took over his practice seems to be competent.

However, lacking the personal connection with the new fellow, I find it hard to justify driving 30 miles to San Jose when there are other skilled opthalmologists nearby.

Our visit yesterday tipped the balance. We asked to use the restroom, and the receptionist told us to go to the Starbucks a mile away. At Starbucks the baristas said that the restrooms were not for customers (we offered to purchase something) but for employees only. They directed us to a Chipotle across the street, where we bought a burrito and used the facilities

A half an hour later we were back for the eye exam, which went as expected.

We don't blame the opthalmologist or Starbucks for the unhappy experience. The responsibility rests with COVID-19, public health regulations, and most significantly the homeless population that makes it difficult to find a restroom in an urban setting.

The businesses in the suburbs are far more relaxed about these things, which is why we will be changing doctors.

A Happy Result

After my opthalmologist retired from practice, I had not had an eye exam for four years, until yesterday.

The Redwood City Costco's optometrist-in-residence runs an efficient operation in a compact space. The various machines are placed on one table, and the patient moves down the line for the various tests plus photographs of the retina.

When the doctor went over the findings, they were better than expected. The cataracts had grown, but the corrected vision will still be good enough to pass the DMV test. There's no urgency in having cataract surgery.

In addition to eyeglasses she will prescribe hard contact lenses, which cost $80 apiece and were much cheaper than the $600 per year for soft lenses.

I expressed surprise about the contact-lens recommendation: Costco sells three different kinds of soft-lens solutions and none for hard lenses, which I assumed were passé for medical reasons.

She said that few people select the latter because of the time it takes to adapt to the irritation, and Costco only sells items that move. However, since I was acclimated 40 years ago there's no reason to go soft. Besides, soft lenses are bad for the environment.

From the start of the exam to the ordering of the glasses and lenses only an hour had elapsed. There's no surgery required now--as well as no glaucoma or macular degeneration--and I'll soon see better.

Once in a while a medical visit yields a happy result.

Dispelling the Fog

(WSJ graphic - click to enlarge)

At the beginning of the coronavirus panic we were given a few rules:
1) stay indoors as much as possible;
2) wash hands frequently;
3) practice social distancing;
4) wear a mask;
5) stop touching our face.

Recently we haven't heard much about touching our face---btw, what's up with that?---but that dictum made me switch from contacts to glasses two months ago. (We wouldn't want to stick washed and sanitized fingers in our eyes because rules.)

But wearing spectacles led to another problem: they fog up when wearing a mask, especially when exercising.

The WSJ describes a simple trick: place a folded tissue inside the mask at the top. It's the most useful advice I've read in the paper all week.

Surprising Development

Costco Optical will never run out of pliers.

At Costco Optical one can order prescription eyeglasses for $130--more if you want fancy frames, lenses that darken in the sunlight (polychromic), or multi-focals.

I chose the cheapest option--why invest in expensive glasses when cataract surgery is a likely possibility?

I' m exclusively an eyeglass- and hard-lens-wearer. Hard contact lenses last at least three years, and I can't, er, see disposing of soft contact lenses every day. Soft lenses encourage behavior that is bad for the environment: Flushing Your Contacts Does Terrible Things to Our Land and Oceans

For a lot of people, contact lenses are a daily necessity. Market research shows 45 million Americans, about one in eight, wear contacts, meaning the United States alone consumes somewhere between five and 14 billion lenses annually. And now, new research shows all those contact lenses may end up as micro-plastic pollution in our soil, rivers, and oceans.

An estimated 20 percent of contact-lens wearers, studied as part of a 400-person online survey, flush their lenses down the sink or toilet, as opposed to placing them in the trash as industry experts recommend. That amounts to 20 metric tons of plastic, or 20,000 kilograms (about 44,000 pounds), flushed per year—about the weight of a small airplane. The biggest culprit? Daily-use lenses, which occupy about 40 percent of the market.

As I slouch into my dotage, one surprising development has been that many of my penurious ways (transportation, cooking, consuming) have turned out to be friendly to the environment.

Things Will Get Brighter

High-res picture of my lens and retina.

"But doc, you said it would be ten years before I had to do something about it."

In 2015 he had spotted a cataract growing in my left eye.

Today he told me that the lens had clouded to the point where I could justify having the surgery now. He pulled out one of the favorite doctorly strategems ("if it were my eyes...")

[Sigh] at least the timing was propitious. It's open enrollment for another couple of weeks, so I'll check out the providers who cover cataract surgery in 2018.

I'm aware of one bad experience, but the dozen or so other acquaintances who have gone through it had excellent results.

Keeping an Eye on It

The ophthalmologist compared the scans with those taken two years ago. The faint shadow had grown.

"You don't need to do anything about it now, but you will need cataract surgery in 10, 15, or 20 years."

The doc wasn't very encouraging about whether I could do anything to prevent the condition from worsening. Some evidence exists that diet and wearing sunglasses outdoors could arrest the development of cataracts, but currently there's little consensus. In the meantime there's no downside to trying those measures.

On the whole the news was good: eye pressure was normal, and the nearsightedness hadn't worsened. I typed in a reminder on the iPhone to come back next year. In the 21st century eyesight is the sense that one can least afford to lose.

The Long and Short of It

Optimal moisture retention is not
always the goal (vippeextensions.com)

Last year Dr. David Hu of the Georgia Institute of Technology made an eye-opening discovery [bold added]:

no matter what species of mammal he examined (and he studied 22 of them), the length of its [eye]lashes was on average a third of the width of its eye.

A good scientist doesn't stop with the observation. He asks why:

he and his team built a small wind tunnel, and also models of eyes that could have their ersatz lashes swapped for ones of different lengths. Using these, they studied airflow around and through the lashes, how that affected evaporation from the model eye's cornea, and also how many particles (in the form of dust-sized drops of coloured water) settled on the cornea's surface. They then used fluid mechanics to try to work out what was going on.

Nature has, it turns out, arrived at the optimum eyelash length to keep the cornea moist and dust-free. By reducing air flow over the cornea, eyelashes create a boundary layer of slow-moving air. That stops dust getting through, and also promotes water retention, since moisture is not blown away. Up to a point, the boundary layer grows thicker as the lashes grow longer. But long lashes also act as a funnel, channelling moving air into the eye and disrupting the protective layer. The thickest boundary layer comes when there is a one-to-three ratio between lash length and eye width.

If lashes are longer or shorter than one-third the eye-width, the eyes dry out....math found in nature that's not as meaningful as the golden mean or Fibonacci sequence, but certainly less mysterious.

Optometry Visit

Modern optometry equipment

My night vision seemed to be less acute, so after nearly a decade it was time to visit the optometrist. The doctor's assistant asked whether I'd like to forego eye dilation.

Using a new LED camera system a high-resolution picture would be recorded in less than a second. There would be no eye drops, no shining of a bright tungsten light into the widened pupils, and no optometrist breath a few millimeters away from my eyeball. I immediately agreed to the $30 additional expense.

After a few minutes of staring at letters and answering a series of Which is better? One or two? questions, he determined that the myopia and astigmatism had not gotten worse. However---and then a close-up of an eye filled the four monitors---there was a faint shadow developing on the left lens.

Someday the cataract may need to be treated, but for now we'll just keep an eye on it. The sunlight didn't cause me to squint as I went back to the car. It was an enlightening visit. © 2013 Stephen Yuen