How Far Can We See? - Interesting Vision Facts

Horizon - Sunrise at Calgary
Horizon - Sunrise at Calgary | Source

A question I frequently hear from my eleven-year-old granddaughter who lives with me is, "Grama how far can you see?" For her, the question is really all about "How far can she go within my line of vision, without an adult accompanying her?"

However, for me, that kind of question has been just one more daily reminder, that I have never been able to see as far, or as clearly as I long to.

Today, however, is a day of miracles. For today, I received prosthetic contact lenses. For the first time in my life (sixty years), I am able to see through both eyes, instead of just one. For the first time in my life, I have depth perception and 20/20 vision.

Goodbye on a daily basis to the trifocals that never fully corrected my vision. Today, I saw my eyebrows and eyelashes for the first time in years. Today, I could look across the room and read the crawler at the bottom of the news channel. Today, I see a whole lot that needs to be dusted around my house. This is huge and makes me immensely happy! (The only negative I saw, was an overnight appearance of some wrinkles on a familiar strangers face when I looked in the mirror).

In celebration of this life altering event -- I thought it might be fun to share what little I know about how far we can see.

Did you ever stand beside the ocean, and wonder just how far that horizon you were looking at -- really was from you?

Did you gaze from the shore and wonder how close that ship on the horizon truly was, and could you really swim to it?

Or maybe, you were out west, standing on a plateau or cliff looking far off to where the sun sets upon the horizon. Maybe, if you had a mind to, could you just walk off into the sunset, or would it be too far?

These are the kinds of things that daydreams are made of, and there is a fairly simple formula for determining how far mankind can see.

Halekala Crater
Halekala Crater | Source

Just How Far Can Mankind See?

In the simplest terms -- When we say that our eyes see, all we really mean is that light has entered them and has affected them. When that happens, we see. It does not matter whether the light has been produced by a match that someone has held in front of our eye, or whether the light has come from a star so distant, that its light took ten thousand years to reach us.

In either case, if light enters our eyes in sufficient quantity to affect it, we see. The answer to our question, therefore, is that our eyes can see to any distance from which light can reach them. The question is, whether the light has that traveled billions and billions of miles, or only half an inch, which makes not the slightest difference to our eyes.

It is quite a distinct question, however, at what distance our eyes can distinguish the details of a particular thing. This depends on many variables, but it can be reckoned to some extent.

We know that if there were any building on the moon as large as some of our big sky scrapers, it could be recognized in our best telescopes. Standing at any given point, we can usually see what is called the horizon, from the Greek word horos, which means "boundary."

Maui
Maui | Source

In this case, the horizon means the boundary between the earth and the sky. We understand, of course, that the line we see on the horizon -- is not really the boundary between earth and sky, but merely the boundary between them as they "appear" to our eyes.

As we stand by the seashore, the sky and the sea seem to meet. We can see a line which seems to be the end of the sea and the bottom of the sky. That is the horizon.

Similarly, if we stand on a plain or plateau of land we can, if there are no trees or houses in the way -- see where the end of the land "seems" to touch the bottom rim of the dome we call sky. That is also the horizon.

Its distance depends on how high our eyes are from the level of the sea, if we are looking across the sea, or from the level of the land across which we are look, or if we were looking over a plain.

Leaving Molokini
Leaving Molokini | Source

Scientific Explanation

A person standing on the shore looks out on the sea, from a distance about five feet higher to six feet higher than the level of the sea (depending upon their height). Using the height of their eyes from seal level, roughly a person can see more than two and one half to three miles in front of them. Their horizon is just this distance away.

The eyes of the individual on the edge of a cliff, on the other hand, could be one hundred feet or more above sea-level, and in that instance, they can see about thirteen to fourteen miles off, for that is where their horizon is.

Then, if you were standing at the top of a lighthouse that is one hundred and fifty feet above sea-level, and if you looked out on the sea from this point, you would see about seventeen miles, and your horizon would also be the same.

The scientific explanation of all this would be that "range of vision is determined by the altitude of the observer." In simple language, this means that the higher up we are, the farther we can see. That is because our world is a globe.

Chart for estimating distances in how far to see
Chart for estimating distances in how far to see | Source

Perhaps, we can understand better how this is if we stand in front of a row of houses forming a bulging crescent. Let us stand close to one of the houses and turn our heads first to the right, and then to the left. We cannot see much of the row of houses -- perhaps only a little bit of the house on each side of the one in front of which we are standing.

We step back into the middle of the street and look again. Now, we can see a good many more of the houses, but still not all, if the row is long. Then, we cross to the far side of the street, and many more will come within range.

To look for the horizon is much the same thing. The earth is round, and the farther we are above the ground along which we are looking, the farther we can see.

In the table I've made above, is shown how far anyone can see at various distances from the earth's surface. In the grand scheme of life it probably doesn't matter if we know how far off the horizon is, but it makes for pleasant debate to throw out that bit of simple knowledge -- especially with children.

They are always amazed to learn that at the one mile high -- we can see about ninety-six miles.

NOTE: The figures are approximate, as the table was drawn up for simplicity, and so it avoids small fractions.

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Comments 35 comments

greatlove profile image

greatlove 5 years ago from Beaufort, NC

Nice hub thank you for sharing. Congrats on your new vision.


Jerilee Wei profile image

Jerilee Wei 5 years ago from United States Author

Thanks speedbird! Glad you enjoyed it and found it useful.


speedbird profile image

speedbird 5 years ago from Nairobi, Kenya

Great hub, nice videos, images and even the layout. Truly amazing vision facts. Voted up and rated USEFUL


Jerilee Wei profile image

Jerilee Wei 6 years ago from United States Author

Thanks Joy At Home!

Thanks electrisky!


electricsky profile image

electricsky 6 years ago from North Georgia

Thanks for sharing your new great appreciation of good vision.


Sexy jonty profile image

Sexy jonty 7 years ago from India

Very well written hub .....

very much informative ......

Thank you very much for your great hub, for good advice, good wishes and support. Thanks for sharing your experience with all of us.


Joy At Home profile image

Joy At Home 7 years ago from United States

The volume buttons were already depressed...like they appear on You Tube when the sound has been deliberately removed from the video. Who knows? I checked all the volume controls on my end. :-)


Jerilee Wei profile image

Jerilee Wei 7 years ago from United States Author

Thanks lyla! It was an unexpected blessing after a lifetime of low vision.


lyla profile image

lyla 7 years ago from India

Jerilee..glad for you and I do share your happiness.Your joy vibrates through this hub!:) Great hub and thanks for sharing!:)


Jerilee Wei profile image

Jerilee Wei 7 years ago from United States Author

Thanks Joy At Home! They are working here on this end, are you sure someone didn't turn your volume off or way down? That sometimes happens here.


Joy At Home profile image

Joy At Home 7 years ago from United States

Great hub...except two of your videos have no sound. The interviews are not much good. :-)


Jerilee Wei profile image

Jerilee Wei 7 years ago from United States Author

Thanks cgull8m! I don't know about the poet part, don't do much of that anymore, preferring poetic wording in bodies of writing these days -- but do love reading good poetry of others.


cgull8m profile image

cgull8m 7 years ago from North Carolina

Jerilee, it is great they fixed your eyes, this world is too beautiful. I felt the same when I started wearing the glasses for the first time. I was stunned how beautiful it was when I was 10 years old :) Enjoy the world, you are soon going to be a poet :)


Jerilee Wei profile image

Jerilee Wei 7 years ago from United States Author

Thanks James A Watkins! The best compliments are the ones that tell me my readers have gained something by what I wrote.


James A Watkins profile image

James A Watkins 7 years ago from Chicago

Your daughter is a great photographer.

I love your subject and your presentation is interesting and flows very nicely. I enjoyed it very much and I learned some things. Thanks.


Jerilee Wei profile image

Jerilee Wei 7 years ago from United States Author

Thanks Dolores Monet! Indeed it is and always has been a beautiful world.


Dolores Monet profile image

Dolores Monet 7 years ago from East Coast, United States

Jerilee, I love how you mix the poetic into science...or is it just that the science is poetic? I am glad for the wonderful technology that so improved your vision - what a gift, it's a beautiful world, ain't it?


Jerilee Wei profile image

Jerilee Wei 7 years ago from United States Author

Thanks LondonGirl! I was surprised at how many people didn't realize that it's possible to figure such things out, glad to know I wasn't the only one who studied it.


LondonGirl profile image

LondonGirl 7 years ago from London

Great hub - I remember discussing this in physics lessons when I was about 14 or 15, and being fascinated by it. Glad your new contacts are working out well!


Jerilee Wei profile image

Jerilee Wei 7 years ago from United States Author

Thanks Nolimits Nana! Glad to be of help.


Nolimits Nana profile image

Nolimits Nana 7 years ago from British Columbia

There's vision and then there's vision. Your hubs reveal that your inner vision is excellent. I'm glad to hear your other vision is matching it!

Thanks for the links also - I'd never found some of the other hubs on vision and eye health. I'm on the computer for several hours a day, and found the tips in one or two of them really helpful.


Jerilee Wei profile image

Jerilee Wei 7 years ago from United States Author

Thanks ReuVera! Janet is my talented daughter.


ReuVera profile image

ReuVera 7 years ago from USA

I loved the pictures by Janet Welch. Very beautiful. Thank you for interesting information too.


Jerilee Wei profile image

Jerilee Wei 7 years ago from United States Author

Thanks Ginn Navarre! Mom -- I remember very well being fussed at by everyone about turning my head to the side to see. Then, later as an adult when I was diagnosed with visual problems, I was almost relieved, because then I at least had a reason for being so uncoordinated at sports, etc. I don't know about civilian hospitals and doctors, but the VA is on the cutting edge with both technology and fresh young doctors who really seem to know what they are doing.

I've thought about your mirror suggestion but that would only work if I can learn to take the contacts out without a mirror. Love you.


Ginn Navarre profile image

Ginn Navarre 7 years ago

Jerilee yes, isn't technology great? How many times did I tell you to look straight at the TV when you were little, not knowing that you could not see correctly with both eyes. That stranger that you now see in the mirror with some wrinkles here and there, well I can solve that problem ---I stopped looking in the mirror years ago, love ya, MOM


Jerilee Wei profile image

Jerilee Wei 7 years ago from United States Author

Thanks Hawkesdream!

Thanks Anthony James Barnett!


Anthony James Barnett - author 7 years ago

You've done it again, Jerilee. Interesting Hub - good stuff.


Hawkesdream profile image

Hawkesdream 7 years ago from Cornwall

Congratulations Jerri, on the 20/20 vision , pleased for you that it was a success.


Jerilee Wei profile image

Jerilee Wei 7 years ago from United States Author

Thanks Storytellersrus! They are making a lot of strides in vision correction. I'm very fortunate as I received all my medical care through the VA and they really do a good job in seeing to it that you can see.

Thanks Nancy's Niche! While it may be a small thing, for me to see clearly is huge!

Thanks lphigenia! It's totally amazing to be able to see clearly! I've always thought it interesting about horizons, especially that even your own height enters slightly into how far you can see.

Thanks Feline Prophet! Perception is everything and right up there with attitude.


Feline Prophet profile image

Feline Prophet 7 years ago from India

So glad that you can see clearly now! :)

As for the rest, it's all a matter of perception, isn't it?


Iphigenia 7 years ago

How exciting for you - it must be so amazing to see details after so many years. I feel so happy for you - so thank you for sharing your happiness.

The rest of your hub is fascinating -something that I had never though about was that the horizon is different for eveybody, that's quite poetic ....


Nancy's Niche profile image

Nancy's Niche 7 years ago from USA

Great hub and full of important info...Congrads on your contace lenses and enjoy each moment of beauty...


Storytellersrus profile image

Storytellersrus 7 years ago from Stepping past clutter

Jerilee, I am so happy for you! I agree with Teresa- that is the most fascinating part of this hub. The rest is trivial compared to this wonder of prosthetic contact lenses. WOW. I have never even heard of these. Congratulations Congratulations Congratulations. May you never lose the excitement of this visual moment in time.


Jerilee Wei profile image

Jerilee Wei 7 years ago from United States Author

Thanks Teresa McGurk! I'm giddy with all the little things, like being able to go to the grocery store and read the fine print on the labels and finally be able to use my expensive camera whose digital icons I can finally decipher.


Teresa McGurk profile image

Teresa McGurk 7 years ago from The Other Bangor

The scientific stuff is all great -- but your contact lenses are brilliant. I'm SO happy for you! That's the really exciting part of your hub for me.

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