1.COMPUTER SYSTEM
The VDT, Video Display Terminal, is unlike a book on your lap, straight infront of the user, making it more susceptible to visual interference(glare, distracting background objects, room light intensity variations). Amirror effect can occur. The "straight ahead" screen puts different eyemuscles to work, leading to visual stress.
The contrast on the screen is very important. A dimly lit work environmentworks best. The eye has less adjusting to do, when shifting back and forthfrom the low light intensity of the computer screen to the varyingbrightness of the room. Use a desk lamp to provide light for the printedtext. Avoid getting glare from the lamp on the screen.
Screen colors are important . Avoid red and blue screen characters. Idealcolors are in the middle of the light spectrum . Use green, yellow , andorange characters.Choose a color that feels comfortable to look at. Most screen use lightprint on a dark background (opposite what you see in a book black on whitebackground.) Research is inconclusive about what is better. Try it bothways to see which feels better, try varying it thru the day. Adjust thescreen brightness and contrast for maximum comfort. The character sizeshould be 2.5-3.0mm and be in sharp focus. The resolution of the printdepends on the dot matrix dimensions. 7x9 is best; 9x11 is better. The fonttype should be an easy one to see at a glance.
Check your VDT every 6 months to see that it is operating at themanufacturer's specifications . Look at the manufacturer's guide on how tomake periodic inspections. This will maintain text character quality .Screen filters help eliminate glare and static . Filters with polarizingproperties trap light reflected from the computer screen and so enhancescreen contrast.
Be sure your filter doesn't make the screen darker and reduce the characterreadability. Static and dust on the screen need to be cleaned daily with ananti-static spray or cloth. Cover the terminal at night . The best filtersare, of course, the most expensive .
A VDT visor is an economical way to reduce glare and reflections . Use adetachable keyboard so it can be set in a comfortable position.
II.COMPUTER WORK STATION
COMPUTER WORKING DISTANCE
Recommend: 20 inches (50 centimeters)The line of sight to the top of the screen: Recommend 20 degrees belowhorizontal. The line of sight to the bottom of the screen: Recommend 40degrees below horizontal.
MANUSCRIPT HOLDER:
Recommend text to be at the dame level as the display screen, thus at sameeye level as the VDT 'TERMINAL SPECTACLES': Recommend special glasses asprescribed for the patient by their doctor to suit the needs of the patient
COMPUTER FURNITURE AND WORK SPACE DESIGN
Avoid chairs that are awkward and uncomfortable when trying to see thescreen or use the keyboard. Use an adjustable pneumatic chair with back(lumbar) support. A swivel chair with a sturdy base on coasters is good.The VDT should have a tilt and swivel base. This helps control glare andscreen reflections. Copy holder is needed to hold the text at the samedistance and height at the screen . The copy can be placed between thekeyboard and the screen. Control your work space to gain comfort,functionality, privacy. This enhances your efficiency. Consult computercatalogues to see what might work well at your station.
Eliminate glare from overhead light and windows. Rotate the screen awayfrom glare. Use filters, but watch our for any loss of screen contrast. Setthe room temperature so you are "comfy". Try to get some fresh air intoyour space. Reduce room illumination; try to get a dimmer switch so you canregulate the light . The room light should be 3 time brighter than the VDTscreen background. Use a desk lamp to see your text . Paint the room wallsin flat matte finish or pastel color. Position your desk so you can look upand see across the room or out the window. Get up and walk around and lookfar away on your breaks . Keep your work area "quiet." Cover a high impactprinter to cut down on noise.
III. THE COMPUTER USER
1.Use artificial tears thur the day to moisturize your eyes from the dryair. Do complete blinks while waiting for your screen displays to change.We tend to not blink when doing visually demanding tasks.
2.Contact Lenses. BLINK! 6-15 times per minute . Drink 6-8 glasses of waterper day . Use artificial tears to rewet the eye and contact lenses . Re-clean your lenses after lunch.
3.Computer Eyeglasses. These are prescribed according to your visual systemfunctions, your age, and the distance of your eyes to the computer screen.(MEASURE IT!) Consider these as a part of your work attire, an "occupational tool" like a welder would consider his special safety filterglasses . OVER FORTY? Get computer bifocals ( top lens for the screen,bottom lens for seeing printed text) or computer trifocals or PAL'sprogressive addition lenses (invisible bifocals).
4.Routine vision exams. As times flies, your eyes change. Get itchecked!
5. Posture . Keep your feet on the floor. You may need a foot rest if youare short . Keep the trunk straight , but inclined forward slightly fromthe hips .Keep the wrists straight while typing . Don't rest the wrists onsharp edges. Keep the thighs horizontal with feet flat.
The upper arm should be straight vertically. The forearm should behorizontal or slightly lower than that while typing . Keep your legs fromhitting on the bottom of your desk.
6. Breaks ."20/20 Rule". After 20 minutes, look at distant objects for 20seconds. On data entry: break 10 minutes every hour. Get up and walk orexercise in your chair. The National Institute of Occupational Safety and Health recommend taking a15 minute alternate task break every hour if you are a full-time user. The above information is general in nature and may not be applicable toeach patient and their needs. Routine vision examinations are recommended.
EYE EXERCISES
1.Palming . Close your eyes and cover them with warmed, cupped hands.Rest your cheeks on the heel of your hands. Breathe deep and slow . Relax,imagine the beach or mountains or wide open spaces and try to see it withyour mind's eye.
2. Calendar-Book Rock. Look at your book propped up at about 16 inches.Focus on it. Look at the calendar or clock acro.
Sunday, December 2, 2007
COMPUTERS AND YOUR EYES
Computer-eye interactions put a heavy demand on our visual system, whichwas developed over centuries to serve man as "the hunter." Only in the lastcentury has man begun to rely on his reading vision for his survival. Heavyloads of close reading or computer work can induce "distress".
Symptoms include: eyestrain, headaches, itching and burning, scratchysensation, blurring of vision, doubling of vision, and color perceptionchanges . Indirect symptoms can be : neck, shoulder, back and wrist pains,fatigue, and general stress, leading to lower job performance and decreasedvisual efficiency.
A National Academy of Science report suggests that simply improving theergonomic condition of the worker could reduce vision complaints by up to39% . The computer work environment includes many different factors that can be controlled, including lighting, user position, computer placement,noise, air quality.
Symptoms include: eyestrain, headaches, itching and burning, scratchysensation, blurring of vision, doubling of vision, and color perceptionchanges . Indirect symptoms can be : neck, shoulder, back and wrist pains,fatigue, and general stress, leading to lower job performance and decreasedvisual efficiency.
A National Academy of Science report suggests that simply improving theergonomic condition of the worker could reduce vision complaints by up to39% . The computer work environment includes many different factors that can be controlled, including lighting, user position, computer placement,noise, air quality.
Friday, November 16, 2007
Small Incision Surgery and its results
HOW IS SMALL INCISION SURGERY PERFORMED? Small incision cataract surgery is performed on an outpatient basis. Beforesurgery, the patient is given as anesthetic to numb the eye and keep themcomfortable during surgery. Most patients return home a few hours after theprocedure, with little or no need for pain medication.
WHAT RESULTS CAN BE EXPECTED AFTER SMALL INCISION SURGERY?
Most patients can expect a rapid return to good vision following smallincision cataract surgery. In many cases, patients are able to seerelatively well the day after surgery without glasses. However, somepatients will need to wear glasses for reading and other activitiesfollowing the procedure. Quickly returning to an active lifestyle is one ofthe primary benefits of small incision cataract surgery.
IS SMALL INCISION CATARACT SURGERY FOR EVERYONE?
With the small incision techniques, fewer or no stitches are needed thanwith traditional techniques . However, the size of the incision and thenumber of stitches used varies from patient to patient. Some patients ,because of their eye structure or other health factors, are not goodcandidates for small incision surgery. In these cases, patients can havetraditional surgery and expect to do well .
SIGHT LOSS CAN BE PREVENTED
Although there is no way to prevent the development of cataracts, loss ofsight from the disease is largely preventable. With modern technology,cataracts can be removed and good vision restored. Cataract surgery can beperformed when a loss of vision begins interfering with daily activities
Thursday, November 1, 2007
WHAT IS A CATARACT?
A cataract is the clouding of the lens of the eye. Normally , light passesage through the clear lens and is focused onto the retina. However, as a result of the natural aging process, the lens gradually becomes cloudy. Thecataract or cloudy lens blocks the passage of light through the eye and causes distorted or blurred vision . The above image is an quite comprehensive example for understanding the CATARACT problem.
WELCOME, TAKE CARE OF YOUR EYES, IT'S A PRECIOUS GOD'S GIFT
Hi welcome watch important videos on small incision cataract surgery (SICS). And know how the modern technology helps the mankind to overcome this problem. Thanks to the technology for giving us back our real vision.
Subscribe to:
Comments (Atom)