Out, damned spot!

What was troubling Lady Macbeth when she spoke these words was perhaps more troubling than when most people see ‘spots’. Persistent spots in one’s vision, otherwise known as ‘floaters’, are common and generally nothing more than an inconvenience and a bit of a distraction. These annoying spots can, however,  also be warning signs of something more sinister.

To see your own spots, look at the blue sky, a clouded sky, or a blank wall. Make sure there is plenty of light. Cover your left eye with your hand, but don’t touch the left eye and don’t close it – leave both eyes open. With the left eye covered over, look at the wall/sky with the right eye. Try to look ‘through’ the wall/sky, just let your eyes relax. Look only in one direction and avoid other objects like buildings, trees, wall hangings/photos, etc. – look only at a ‘blank screen’, either sky or wall. Pay attention to what you see. You will almost certainly notice some floaters or strings, probably slowly moving downwards, sideways, and rarely upwards. Now, quickly look side to side, and up and down, then look again the same direction as you were at first. You will now notice the floaters have shifted position and are starting again to resettle in the eyeball. Uncover the left eye and cover over the right eye. Again, it’s best if you don’t close the eyes or touch them with your hands for this activity. Repeat the activity with your left eye. Once you get to know what floaters are present in each eye, look at the ‘blank screen’ with both eyes. See if you can tell which eye is contributing which floaters to the total scene. It’s worthwhile getting to know your own floaters; as you will see, this can save your sight.

To understand spots and why some are boring and banal, while others are more interesting and dangerous, we have to take a quick tour of the inside of the human eyeball. Look at your eyes in the mirror. You will notice an eyeball that is mostly white (the sclera), then a colored ring with a hole in it (the iris). The hole is your pupil, and in a healthy eye, it will change size depending on light levels – bright lights, small pupil. (Drugs, disease, and nerve damage will also cause the pupils to change size, or not move at all.) The pupil appears black because there are no lights inside the eye, it’s like looking into a cave – can’t see the other side. Immediately behind the colored iris is the lens, a small pea-sized ball of soft, clear, rubbery tissue. A small ring muscle, the ciliary (‘silly airy’) body, surrounds the lens and tugs and releases it to help to focus light onto the back of the eye (the retina).

Most of the volume and mass of the eye is from the inner contents, the stuff between the lens at the front of the eye and the retina at the back, what we call the vitreous. Vitreous is from the French ‘vitre’, which means glass. So, the vitreous is a clear gel that accounts for most of what you find in the eyeball. When the eye is cut, the vitreous slides out, like soft warm jello. It’s contained within very thin membranes, like long balloons, each containing an amount of the clear jelly. When we are young, this jelly is more firm. As we age and gravity takes hold of our bodies, the jelly also sags, turning more to water than jelly, and starts to slosh about within the eyeball. This action causes the fine membrane bags containing the vitreous to move about, break apart, and even become detached from the inside of the eye. This breaking apart of the eye’s inner contents leaves small particles floating around inside. The membranes will also shift around, giving the appearance of strings, or waves. Technically speaking, we call this sort of trouble a ‘posterior vitreal detachment’, or PVD.

PVD’s occur with age, and also for people who experience head trauma and direct impact to the eyes – either through work, sport, fighting, or accident. Spots are normal, in other words. That is, small spots and strings that have been with us for what seems like ages, these are normal. PVD’s, however, are associated with a greater risk of retinal detachment, something that can rob you of your sight. When the sensory tissue of the eye, or retina, detaches from the outside wall of the eye, you are effectively blinded. Only when surgery repairs this damage do you have a chance of recovering your sight.

In other words, PVDs are not much of a problem, while retinal detachments (RD) will blind you. Both are associated with spots and strings. How do you tell the difference to know that you’re having trouble?

First Rule of Floaters: If in doubt, there is no doubt. Go see your optometrist immediately to make sure nothing is seriously wrong. Why an optometrist? Unlike family physicians, optometrists have years of training in eye and vision disease, and they can usually see you on a moment’s notice if you’re having this sort of trouble. It’s also a fraction of the cost to healthcare when you see optometrists for eye care problems, 1/10th of the cost of going to the emergency room. The service is covered under healthcare.

Second Rule of Floaters: Get to know your own floaters. Changes in floaters, or new floaters, should be checked. This is usually very quick and involves a ‘dilated’ eye exam, where drops are used to relax the iris to make the pupil bigger so the doctor can have a good look all around the inside of the eye. You should be sure to bring sunglasses to this exam.

Third Rule of Floaters: PVDs are fine, RDs are bad. Signs of RDs, retinal detachments, are: changes in floaters; the presence of new, usually bigger floaters; the appearance of flashes of light; the appearance of a curtain or cloak over the vision, like part of your vision is missing, usually from the top or sides; the appearance of red in your vision, indicating broken blood vessels. These usually appear fairly quickly, often within hours, but they can also creep up on you over days.

If you are experiencing any such trouble with your vision, you need to be checked immediately. Again, this service is available through local optometrists and is covered under Alberta Healthcare. If you have any concerns about your eyes or vision, do not hesitate to take immediate action, it can save your sight. Contact us if you have further questions at www.dvvc.ca.

 

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