Floaters, Flashes & Retinal Tears

Floaters

Retinal Detachment

Older people often notice occasional spots or opaque flecks drifting across their line of vision, particularly when they are looking at a page of a book, a computer screen, or a solid, light background. These floaters are tiny clusters of cells or gel in the vitreous cavity, where the clear jelly-like substance called vitreous humor fills your eyeball. What you actually see is the shadow these little clumps cast on the retina. In some cases, the vitreous gel may detach from the retina, causing more floaters, an event called posterior vitreous detachment.

About 25% of people have these vitreous detachments and floaters by their 60s, and 65% by their 80s. Floaters also appear more often in people who are nearsighted or have had cataract surgery. These phenomena are usually nothing more than an annoyance and often dissipate on their own. If they occur suddenly, however, consult an ophthalmologist. Certain eye diseases or injuries can cause them. Floaters can also be small drops of blood from a torn retinal vessel. Less commonly, new floaters are the sign of a retinal tear, which should be evaluated.

Once floaters have been checked and declared harmless, one of three things may happen. The floater may disappear as it breaks apart or settles; the floater may become less noticeable with time; or it may stay and become bothersome. Floaters can be removed, but the surgical risk is greater than the floater itself. If floaters become a nuisance to central vision, moving the eye up and down or left and right may shift the floaters and provide temporary relief.

Flashes

Seeing shooting stars — a phenomenon called photopsia — is not unusual as people age. Solitary flashes appear as sparks or minuscule strands of light, almost like streaks of lightning across the sky. They occur when the vitreous gel bumps, rubs, or tugs against the retina. Generally harmless, they require no treatment. In rare cases, they may be a sign of more severe retinal complications. If their appearance is sudden or accompanied by a shower of floaters or a loss of peripheral vision, see your ophthalmologist. These flashes of light are different from the flashing or zigzag lights that may precede migraine headache, which some people experience simultaneously in both eyes, typically for as long as 20 minutes, but sometimes for an hour or even longer.

Retinal tear or detachment

Occasionally, floaters and flashes can be a sign of something more serious: a retinal tear or retinal detachment. In a retinal tear, the vitreous gel pulls on the retina with enough force to tear the retina. Fluid from inside the eye may enter through this tear and separate the retina from underlying tissues that nourish it. Separation of the retina from the back of the eye is called a retinal detachment (see picture). People who are middle-aged and older are the most likely to experience this problem. Nearsightedness increases the chances for detachment, as do cataract removal and eye injuries.

Retinal detachment is a serious condition and can lead to a permanent loss of vision. If you suspect one, contact your ophthalmologist immediately; if you cannot reach your own doctor, go to an emergency room for evaluation. If a tear is caught early, treatment may prevent a retinal detachment. When not treated, the condition may worsen until the retina separates completely from the inner wall of the eye, remaining connected only at the optic nerve in the back of the eye and the ciliary body in the front of the eye. The worst cases cause blindness.

From:everydayhealth

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How the Eye Works

organ of sight is far more complex and efficient. Not only does the eye focus and snap pictures, but it also works continuously with the brain and nervous system to process ever-changing images and provide you with the visual information you need for doing everything from hitting a golf ball to preparing your taxes.

Eyeball Engineering

The conjunctiva is a thin, colorless membrane that lines the inner surfaces of the eyelids and the front portion of the sclera, the eye's white outer layer. The conjunctiva is so sensitive that when it becomes aware of a foreign body, it automatically triggers a protective reaction, such as tearing or blinking.

Six extraocular muscles regulate each eye's up-and-down, side-to-side, diagonal, and rotational motions. The muscles come in pairs and run from the back of the orbit to the sides of the eyeball, beneath the conjunctival membrane (see image "The Inside Story").

The middle layer, called the uveal tract, comprises the iris, ciliary body, and choroid. The iris — the pigmented segment, which might be blue, green, brown, or another color — forms a ring around the pupil, a black hole in the iris's center. Basically a circular curtain of muscle fibers, the iris controls how much light enters the eye. As with an automatic camera, which adjusts the size of its aperture (opening) to the available light, the involuntary muscles of the iris open to allow more light to enter the pupil in dim light, and close to make the pupil smaller in bright light. A good example of the eye's adaptation is the mildly painful change that occurs when you walk into sunlight after sitting in a dark movie theater. Even subtle alterations in light prompt a response from the eye, and the iris muscles are continually adjusting to the environment.

From:everydayhealth

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Living With Low Vision

Many people must live with vision that limits their daily activities, a condition known as low vision. Low vision may involve blurry vision, poor central vision, loss of peripheral vision, or even double vision. Whatever the symptom, the immediate consequences are often the same — difficulty performing day-to-day activities such as reading a newspaper, using a computer, watching television, cooking a meal, or crossing the street. Still, low vision is like many complicated medical conditions: While there may not be a cure, there often are ways to cope.

Optical aids. The magnifying lens remains one of the most common tools to help compensate for low vision. Most magnifying lenses are made to be held, but some can be incorporated into the lens of a pair of prescription glasses and used for reading or detail work. Special lenses that work like miniature telescopes can be mounted on a pair of glasses and used for driving or watching a movie. Glasses with special filters or stand-mounted magnifiers containing a light source may help with excessive glare or reduced contrast (less distinction between light and dark). An expensive option is a device similar to something once featured in Star Trek: goggles that consist of two tiny high-definition television sets that display images recorded and enhanced by a digital camcorder.

Computer aids. Many software programs can make the text on a computer monitor larger or more legible to people with vision problems. Options range from programs that enable you to change font size and background displays to specialized text-to-speech conversion programs that read online text aloud. Special keyboards, magnifiers for monitors, and other devices are also available. Most major computer supply stores carry these products.

Other aids. Electronic "talking" watches, alarm clocks, and calculators let people rely on their hearing rather than their vision. Listening to books on audiotape is another popular option.

A simple desk lamp with a metal shade is one of the easiest ways to improve vision if you use it properly. Position the lamp so that the light shines directly onto the materials in front of you, rather than over your shoulder or high above you.

Other inexpensive, low-tech vision aids include large-print versions of playing cards, bingo cards, and push-button telephone pads. And, of course, many books and newspapers come in large-print versions.

Rehabilitation. In addition to using various gadgets, people with low vision can learn a few simple tactics to compensate for their diminished sight. Ophthalmologists, optometrists, and occupational therapists can offer such advice. For example, dark coffee is easier to see when poured into a white mug, and a fried egg is more visible when served on a dark plate. You can rearrange furniture for easier navigation, and label your foods and medications with large print to make them easier to identify.

From: everydayhealth

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Little Big Pine

In my heart of hearts I hear a voice that whispers:
there really are no countries,
there’s but a single Earth endowed with many lands,
and every land is beautiful; there is no land I would not live.

But somewhere long ago they took away
my native eye, and when they gave it back –
then I saw a world of many rival nations;
then it seemed to me my country was the best.

In my heart of hearts I hear a voice that whispers:
there really are no languages,
there’s but a single Tongue endowed with many sounds,
and every sound is beautiful; there is no sound I would not speak.

But somewhere long ago they took away
my native ear, and when they gave it back –
then I heard a world of many strident dialects;
then it seemed to me my language was the best.

In my heart of hearts I hear a voice that whispers:
there really are no races,
there’s but a single Body endowed with many faces,
and every face is beautiful; there is no face I’d not embrace.

But somewhere long ago they took away
my native face, and when they gave it back –
then I faced a world of many hostile tribes;
then it seemed to me my people were the best.

In my heart of hearts I hear a voice that whispers:
there really are no religions,
there’s but a single Spirit endowed with many paths,
and every path is beautiful; there is no path I would not walk.

But somewhere long ago they took away
my native feeling, and when they gave it back –
then I felt a world of many adverse deities;
then it seemed to me my god was the best.

Somewhere long ago they meddled
with my eyes and ears, my face and feelings;
and still they do not cease.

Yet all I really know
is what I hear that ever whispers
in my heart of hearts.

little big pine
los angeles county
hearing orpheus’ fine harp with naked eyes.

From: stateofnature.org

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In my heart of hearts

The Bard was a logical man, and he went about coining sensible phrases in a rational fashion. Thus, Hamlet does not say "in my heart of hearts," but "in my heart of heart"—that is, at the "heart" (center) of my heart. The phrase is in fact a synonym for "In my heart's core." And like the heart of an artichoke, the heart of Hamlet's heart is its most tender part. He reserves this region of his affection for men who aren't slaves to their passion, who are governed by reason, like his friend Horatio (whom he addresses here) and, indeed, like the phrase-coining Shakespeare.

We've perverted the phrase into "in my heart of hearts" by way of expressions like Ecclesiastes' "vanity of vanities." But where Ecclesiastes had a number of vanities from which to elect a chief or encompassing vanity—presumption—one doesn't have a number of hearts. Even granting that we use "heart" mostly as a metaphor and not with reference to the organ, we never mean to speak of having more than one.

From: enotes.com

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