Eye mishaps are among the most common injuries treated in hospital room. Ophthalmologists have long realized that most of these injuries can be avoided by using simple precautions.
Other useful facts, information and recommendations to preserve your eye health
Reducing eye strain
Your eyes water, your eyelids twitch, the part of your forehead around your eyebrows seems to ache, and you notice a burning sensation when you close your eyes — you’re suffering from eye strain!
Eye strain is common and can occur after the eyes are taxed for a prolonged period, like after hours of work or driving. You can reduce eye strain by taking simple precautions:
Hold the reading material about 30 to 40 centimetres away from your eyes. Take a break every hour or so by looking at distant objects for three or four minutes. Follow the same guidelines for other close work, such as sewing, knitting and drawing.
When watching television…
While watching TV, the lighting in the room should be noticeably dimmer — by about 50 per cent — than the illumination of the screen. Ensure that the lighting doesn’t reflect on the screen or cause a glare. Don’t watch in total darkness either, as the contrast in light is too sharp.
Avoid viewing from an angle. Sit directly in front of the screen at a reasonable distance about four or five times the width of the TV screen, e.g., for a 100-centimetre (40-inch) screen, sit about four to four and a half metres away. Those with poorer sight may need to sit closer.
Despite what you may have been told when you were young, watching TV will not damage a child’s eyes. In fact, children can focus up close without eye strain (fatigue) more easily than adults. There is no evidence that this damages their eyes and it is a habit that usually disappears with age.
Occasionally, children with near-sightedness sit close to the TV in order to see the images more clearly. An ophthalmologist can diagnose this condition and correct it by prescribing suitable glasses.
When looking at a computer screen…
Eyestrain, backache, and muscle spasms may improve with proper (ergonomic) arrangement of the computer screen and seating arrangement.
If you wear glasses, be sure they are adjusted for the distance between your eyes and the computer screen — most computer users prefer to position the screen farther from where they normally read, so ensure prescription glasses are adjusted accordingly.
Take periodic rest breaks — using a computer requires unchanging body, head, and eye positions that can be fatiguing.
Lubricate your eyes by blinking frequently or using artificial tears (lubricating eyedrops). Keeping your workstation clean to minimize eye irritation from dust can also help.
Minimize light glare by adjusting office lights or using hoods or filters on the computer screen — standard office lighting is usually too bright for comfortable computer screen viewing.
Source: Eye Physicians & Surgeons of Ontario
On bright or hazy days, wear sunglasses to protect your eyes from glare and harmful ultraviolet rays. If you’re on a long trip, stop every few hours to rest your eyes and stretch.
Rest usually alleviates eye strain; however, if you suffer prolonged discomfort or notice a marked change in your vision, you should immediately have an eye examination.
Viewing computer screens
Complaints of eye discomfort and fatigue are becoming more common as the use of computer screens increases. While it is true that computer screens can cause eyestrain, there is no convincing evidence that they can harm the eyes.
Some people fear that computer screens emit damaging ultraviolet (UV) light or radiation. The amount of UV light emitted by computer screens is a fraction of what is emitted from a fluorescent light.
Radiation levels from computer screens are so low that a lifetime of exposure will not damage the eyes. After prolonged use of a computer screen, black and white objects may appear colored, but this is not a sign of eye damage.
Symptoms of eyestrain are eye irritation (red, watery, or dry eyes), eye fatigue (tired, aching heaviness of the eyelids or forehead), difficulty in focusing, and headaches. However, eyestrain does not result in permanent eye damage.
Eyestrain, backache, and muscle spasms may improve with proper arrangement of the computer screen and seating area. The Occupational Safety and Health Administration (OSHA) provides helpful suggestions on workstation arrangement.
It is important to wear appropriate eyeglasses adjusted for the distance between the eyes and the computer screen. Most computer users prefer to position the screen farther from where they normally read. Prescription eyeglasses should be adjusted accordingly.
Take periodic rest breaks. Using a computer requires unchanging body, head, and eye positions that can be fatiguing. Lubricate the eyes by blinking frequently or using artificial tears (lubricating eyedrops). Keep workstations clean to minimize eye irritation from dust.
Minimize light glare by adjusting office lights or using hoods or filters on the video screen. Standard office lighting is too bright for comfortable computer screen viewing.
Source: Eye Physicians & Surgeons of Ontario
The dangers of UV rays
Studies have shown that permanent damage to the eyes can result from prolonged exposure to the sun without adequate protection.
Ultra violet (UV) light is the component of sunlight most responsible for eye damage. Excessive exposure, especially from light reflected from sand, snow or pavement, can produce a burn on the surface of the eye.
Like a sunburn on the skin, eye surface burns are usually painful, but temporary.
Of more concern is the cumulative damage of repeated exposure that may contribute to chronic eye disease. UV exposure can affect not only its surface, but also its internal structures (the lens and retina).
UV light is a risk factor in the development of pterygium (a growth that invades the corner of the eyes), cataracts (clouding of the lens) and macular degeneration (breakdown of the macula).
Those at risk include people who spend a lot of time in the sun, those who live at high altitudes or near the equator, and those who take photosensitizing drugs such as psoralens (used to treat psoriasis), tetracycline, doxycycline, allopurinol or phothiazine.
During cataract surgery, the natural lens is removed and replaced with a synthetic lens. Newer intraocular lens implants filter UV radiation. This eliminates any concern about UV eye protection after cataract surgery.
To protect your eyes from the sunlight, it is recommended that you wear a wide brimmed hat and sunglasses that filter out 99-100 per cent of the UV light.
Choosing the right sunglasses
Here are a few tips to help you choose a pair of sunglasses that can protect your eyes from the damage caused by prolonged exposure to sunlight.
First, look at the label. Although universal standards are not in place, most manufacturers label their products stating their protective ability.
The Canadian Ophthalmological Society (COS) recommends that glasses block 99-100 per cent of UV light (both UV-A and UV-B).
If you spend a lot of time in the sun, it is recommended that you buy wrap-around glasses to prevent the sun from entering your eyes from the sides.
Don’t be deceived by color or cost — dark lenses do not necessarily mean good protection. Also, expensive glasses do not guarantee good protection — price may be an indication of better quality or durability, but more often, it is a reflection of current fashion.
Using eye drops
Infections, inflammation, glaucoma, and many other eye disorders often are treated with medicated eyedrops.
It is important to remember that all medicines can have side effects. Surprisingly, even the small amount of medication in an eyedrop can create significant side effects in other parts of the body. There are ways to decrease the absorption rate of the eyedrop into the system and to increase the time the eyedrop is on the eye, making the medicine safer and more effective.
Instilling eyedrops may seem difficult at first but becomes easier with practice. To place an eyedrop in your eye, first tilt back your head. Then create a “pocket” in front of the eye by pulling down on the lower with an index finger or by gently pinching the lower lid outward with the thumb and index finger. Let the drop fall into the pocket without touching the dropper tip to your eye, eyelid, or fingers, so as to prevent contaminating the bottle.
Immediately after instilling the drop, press on the inside corner of the eyelids next to the bridge of your nose for two to three minutes with your thumb and forefinger. This prevents most of the drop from traveling down the tear duct to the back of the throat, where it then is absorbed by the rest of the body. Keep your eyes closed for three to five minutes after instilling eyedrops.
Before opening your eyes, dab unabsorbed drops and tears from the closed lids with a tissue.
If you are taking two different types of eyedrops, wait at least five minutes before instilling the second drop. Because the volume of a single drop exceeds the capacity of the surface of the eye, it serves no purpose to use two drops at the same time.
Source: Eye Physicians & Surgeons of Ontario
Avoiding ‘digital eye’
In today’s world we spend more and more time staring at electronic screens, including mobile phones, computer tablets, MP3 players and handheld gaming units. Viewing backlit liquid crystal displays for long periods can put a tremendous strain on your vision, and have lasting consequences on your eye health. Here are five tips to help avoid ‘digital eye’:
- Blink, breathe, and break — when looking at a computer or handheld digital device you blink two to three times less than you normally would. This can often lead to “dry eye”. That may seem like something inconsequential, but in reality — for power digital users — can lead to permanent vision damage.
- While working on the computer, reading your tablet, e-reader etc., every 20 minutes look 20 feet away for 20 seconds to allow your eyes to refocus.
- Let your eye doctor know if you are a “power user” of handheld devices. Your eye doctor may provide you with a separate lens prescription for digital devices, to lower eye strain and avoid permanent damage.
- Get an annual eye exam to gauge the ongoing impact of using digital devices.
- Monitor lighting — glare and low light can strain your eyes, and when you are looking at a digital device the back-lighting of the device combined with the room’s lighting could be very detrimental.
[Source: ‘Smart Medicine for Your Eyes’, Dr. J. Anshel]
Light therapy for seasonal depression and jet lag
As many as 10 per cent of Canadians may suffer from some sort of seasonal depression caused by sunlight changes.
Commonly called the “winter blues”, symptoms in response to the reduction in daylight during the winter months can include low energy, excessive sleep, over-eating, weight gain and even severe depression. These effects are usually caused by what is commonly referred to as a malfunction of the body’s clock.
Light therapy may help these people, as well as those who work night shifts and or suffer from jet lag from traveling.
As well as sending images to the brain, the eyes also tell our pineal gland, a small pea-sized gland located in the brain, when the day is over. The pineal gland then induces drowsiness by secreting melatonin, a marker for the body’s internal clock. The pineal gland also influences moods, hunger and metabolism.
Doctors have learned to treat seasonal depression and jet lag by using a simple device called a light box.
Because the timing, intensity and duration of the light all play a role in the treatment of each individual case, it is important to stress that the light therapy must be administered by a medical doctor or therapist.
Some cases of corneal burns have been reported by people who have tried to treat themselves, therefore it’s important to first consult your physician if you think light therapy could help you.
Ocular damage and commercial tanning facilities
There is increasing evidence that the use of tanning salons and sun lamps can cause ocular damage.
The Health Protection Branch of Health Canada has monitored the use of sun lamps for some time, as several thousand people are treated each year in emergency departments for the acute ocular effects of sun lamp burns. There is increasing evidence that more serious long-term ocular damage may also result.
The major problem arises from the fact that although the manufacture of the lamps and beds are adequately controlled by federal regulation, the implementation of the tanning process is virtually unregulated.
Tanning operations have to meet sanitation regulations, but health inspectors have no power to ensure that owners use the correct bulbs, make clients wear protective goggles, limit exposure times or screen clients for photosensitizing diseases or drugs.
Viewing a solar eclipse
Looking at a solar eclipse is as dangerous as staring at the unblocked sun and can cause damage to the retina, the light-sensitive nerve layer at the back of the eye. The damage affects the macula, the part of the retina responsible for fine central vision.
Many people think they can protect their eyes by looking through filtered binoculars, sunglasses, neutral density filters, or exposed photographic or radiographic film. However, a retinal burn can occur in spite of all these barriers. In a 1970 solar eclipse in the eastern United States, 145 retinal burns were reported. Forty percent of the injured patients were using protective filters.
Parents must caution children not to look directly at the sun. Not only are children more tempted to watch an eclipse, but the damage is usually more severe because the child’s natural lens is so clear that it lets more ultraviolet (UV) rays reach the back of the eye.
There are safe ways to view an eclipse. Attend a display at a planetarium or university astronomy department, where optical instruments are used to project an image of the eclipse from a telescope to a screen for safe viewing. Alternatively, watch the eclipse on television or use the simple pinhole camera described below.
Take two sheets of plain white paper. Make a pinhole in the center of one of the pieces. Then stand with your back to the sun and hold the sheet with the pinhole in front, so that the sun shines through the pinhole and onto the other sheet of paper. An image of the eclipse will be projected onto this second sheet. It is amazing how well you can observe a solar eclipse with this simple device.
If you suspect that you or a family member might have suffered a solar injury to the eye, consult an ophthalmologist as soon as possible.
Source: Eye Physicians & Surgeons of Ontario