Ho Optometrist

Your Local Optometrist from 怡保……Ipoh….. Perak, Malaysia

Happy Chinese New Year 2013!!!

2013 Year of the Snake

Ho Optometrist would like to wish all who celebrate this Festive Season Happy Chinese New Year!

May the Year of ULAR be Prosperous & Harmony….Gong Xi Fatt Chai!!


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Is your Office Bright enough for your Eyes?

Is your office or workplace comfortable for your eyes? Have you ever felt eye strain,dryness, discomfort after a days of work… It time to check if your workplace is ideal for your eyes with Good Ligthing.

What is the significance of Good Lighting?

Office work is visually demanding and requires good lighting for maximum comfort and productivity. “Good” lighting means providing enough illumination so that people can see printed, handwritten or displayed documents clearly but are not blinded by excessively high light levels (a cause of glare).

What are signs of poor lighting?


The most common complaints resulting from poor lighting are:

  • Difficulty seeing document or screen (too much light or glare, or too little light or shadows),
  • Eyestrain,
  • Eye irritation,
  • Blurred vision,
  • Dry burning eyes, and
  • Headaches.

Poor lighting affects not only the ocular system but can also contribute to stiff necks and aches in shoulder area. These problems can occur when people adopt poor or awkward postures when trying to read something under poor lighting conditions.

A good visual environment will:

  • have sufficient light, coming from the right direction and not cause obscuring shadows,
  • provide good (but not excessive) contrast between the task and the background,
  • limit glare and extreme contrasts, and
  • provide the right type of light.

Why do computers create a challenge for lighting designers?

The monitor itself is a source of light. As such, it does not require additional illumination from other sources. In fact, the screen itself can cause glare if the brightness and contrast controls are not properly adjusted.iStock_000002652059Small

An additional challenge occurs because most office work involves using the monitor and paper documents at the same time. Paper documents require a higher light level than the monitor. A desk lamp (any type of soft task light) can be used to illuminate documents while avoiding excessive light near the monitor. Glare can also result from an improper match or excessive contrast in light levels between the monitor screen and the paper.

The monitor also acts as a mirror. Reflections of objects, shiny walls, and any light source (specifically windows and overhead lighting) all cause glare. Eye discomfort can result but glare also forces the user into an awkward position as they try to avoid having the glare in their eyes. These positions lead to aches and pains in the upper body that, in turn, can also aggravate eye strain.

The quality of the images on the monitor is another important factor. Reading and interpreting blurred, fuzzy, tiny, or otherwise illegible characters for hours a day can strain the operators’ eyes.

What else in the computerized office contributes to the eye discomfort?

Other examples of work-related risk factors that contribute to eye discomfort are:

  • Maintaining a fixed and close visual distance for a long time,
  • Glare from the unshaded or un-diffused lighting fixtures,
  • Poor lighting, involving unchanged (and unchangeable) levels of illumination,
  • Unsuitable workstations (dimensions and arrangement),
  • Low ambient humidity,
  • Uncorrected vision problems, and
  • Lack of colour variety in one’s surroundings.

Are there any non-visual effects of poor lighting?

When people are exposed to glare or have uncorrected vision problems, they tend to lean forward or backward in an attempt to compensate. An awkward body position leads to eye strain and accelerates postural fatigue that, in turn, contributes to musculoskeletal injuries (MSI).


How can eye discomfort be reduced?

Overhead lighting

  • Use filters to diffuse overhead lighting.
  • Dim overhead lights.
  • Keep in mind that recommended level of light in offices 300 – 500 lux is not a must. It applies in the situation where there is no task lamp in use.

Windows and walls

  • Cover windows with adjustable blinds.
  • Use matte finishes on walls, floors and furniture.


  • Adjust the brightness and contrast according to your preference.
  • Use a light colour for the background.
  • Place the monitor parallel (not directly below) with overhead lights.
  • Angle the monitor away from lights and windows.
  • Make sure that the task lamp illuminates the document and not the monitor.

Should anti-glare screens be used?

In general, anything between the operator and screen compromises the quality of the image. It is far better to control glare by proper lighting design and placement of the monitor than by use of an anti-glare screen. Many monitors currently available are already equipped with low reflective screens.

What can you do to reduce eye strain?

The ability to focus on objects at various distances decreases with age (presbyopia). Commonly, by their forties people cannot clearly see objects at close range with the naked eye. This is a gradual change, and has to be regarded as an important component in designing visual environments, particularly when the job involves computer work. Uncorrected vision may be an additional source of eye discomfort. It may have further consequences resulting in aches and pains because of awkward postures or positions adopted to “see better”.

  • Check your vision every one or two years, as recommended by your Optometrist.
  • Provide your Optometrist with information about your job.
  • Consider using task-specific computer glasses.
  • Make sure your monitor is correctly set up.


Depending on the amount of time you work at a keyboard, the kind of vision correction needed, and your personal preferences, your eye specialist may recommend bifocals, trifocals or even a separate pair of glasses for computer work.

Focusing your eyes on objects at the same distance and angle for prolonged periods of time can contribute to eye strain.

  • Every few minutes look away from the screen for a few seconds.
  • Look around.
  • Focus your vision on distant objects.
  • Blink several times.

Frequently “stretching” your eyes like this will prevent feelings of fatigue from accumulating.

Source: http://www.ccohs.ca/oshanswers/ergonomics/office/eye_discomfort.html

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Contact Lenses at Work..

What are contact lenses?


Contact lenses are small, thin discs made of a transparent material. The outer surfaces are custom-shaped to correct or improve vision and the inner side is carefully formed to fit the surface of the cornea (the clear, front covering of the eye including the iris and pupil). Today, the lenses are typically soft (flexible) but hard (rigid) are still available.

Contact lenses can be a safe and effective way to correct vision for most people. However, people who wear them must follow the directions of their eye specialist – this care includes how long the lenses can be worn continuously, how they should be cleaned and stored, and the good hygiene practices to follow when wearing or handling the lenses.

Many people wear contact lenses because they prefer them to eye glasses – contact lenses do not slip down your nose or fog up in the wintertime. A few people, however, must wear contact lenses to have adequate vision (for example, after cataract surgery, or for medical conditions such as keratoconus – a deformity of the cornea).

Contact lenses can cause some problems that do not produce any symptoms that the contact lens wearer may not notice. For this reason, contact lens wearers should have regular checkups with a specialist who prescribes and fits contact lenses.

What is the controversy about wearing contact lenses at work?

Put as simply as possible, the problem is that, according to some people, contact lenses may complicate eye safety.

The arguments against wearing contact lenses in the work environment are based on the following:

•Dusts or chemicals can be trapped behind the lens and cause irritation or damage to the cornea or both;

•Gases and vapours can cause irritation and excessive eye watering; and

•Chemical splash may be more injurious when contact lenses are worn. This increased risk is related to the removal of the lenses. If removal is delayed, first aid treatment may not be as effective and, in turn, the eye’s exposure time to the chemical may be increased.

However, the opposite may be true as well. Contact lenses may prevent some substances from reaching the eye, and thus minimize or even prevent an injury. Both situations have been documented.

As a result, a wide range of opinions about the safety of contact lenses in the workplace has formed. More complete information is hard to find since occupational injury reporting systems do not typically include information about contact lens use.

The critical point to remember is that contact lenses are not intended to be used as protective devices. They are not a substitute for personal protective equipment (PPE) – if eye and face protection is required for certain work operations then all workers, including contact lens wearers, should wear the proper protective devices. Safe work conditions for all workers are only possible when basic occupational health and safety practices and procedures are followed.

Are there situations where it may be hazardous to wear contact lenses?


While these conditions may be hazardous to both contact lenses wearers and to people who do not, contact lens wearers should be aware that certain conditions may make it necessary to avoid wearing their lenses. Each situation should be carefully investigated. These situations may include:

•Exposure to chemical fumes and vapours,

•Areas where potential for chemical splash exists,

•Areas where particulate matter or dust is in the atmosphere,

•Exposure to extremes of infrared rays,

•Intense heat,

•Dry atmosphere,

•Flying particles, and

•Areas where caustic substances are handled, particularly those used or stored under pressure.

In workplaces with ultra-violet and infrared radiation sources, users of contact lenses require protection just as persons not wearing contact lenses do. Contact lens types absorb infrared radiation. This effect is potentially more harmful to the soft lens wearer as it could alter the water balance of the contact lens.

Are some hazards specific to soft contact lens wearers?

Soft lenses are made from a type of plastic that contains a large proportion of water. The soft lense adheres more tightly to the cornea and does not have as much fluid motion as the hard contact lens. For these reasons, some researchers think the soft lens offers some, but not total, protection against entrapment of foreign substances between the contact lens and the cornea.


The major risks for soft contact lens wearers are from chemical splashes and from hot, dry environments. Because of the high water content of the soft contact lens, some chemicals can pass through the lens and be held against the cornea by the lens itself.

Hot, dry environments can lead to problems because they can cause the tear layer (upon which the lens ‘sits’) to dehydrate . This situation results in eye discomfort.

Are some hazards specific for hard contact lens wearers?

Hard lenses are made from an impervious material. Increased risk may result if foreign substances, such as dust or small metal fragments, become trapped behind the contact lens. Since the hard contact lens floats on the tear film in front of the cornea (not in a fixed position), there may be an abrading action between the contact lens and the foreign substance that may result in injury to the cornea. Also, chemicals may become trapped behind the contact lens and held in place against the cornea. In dirty, dusty environments, the wearing of hard lenses may be more hazardous than soft contact lenses.

What are some other possible concerns when wearing contact lenses?

A contact lens wearer working alone or in a remote area may be at greater risk if hurt with an eye injury. The immediate removal of contact lenses may be important and the injured wearer may be unable to do this. Also, equipment (e.g., eyewash stations) and qualified staff may not be immediately available which, in turn, increases the risk of further damage.

Dislodgement or sudden loss of a contact lens is another problem. The first complication creates sudden changes in vision quality due to decreased visual acuity and blurring. These pose obvious dangers if dislodgement should occur at a moment when sight is essential for safety. The same problems could occur for wearers of glasses though contact lenses may be easier to lose and are more difficult to re-position.

Can contact lenses be worn in a hazardous workplace environment?

Be aware that contact lenses themselves do not provide eye protection in the industrial sense.

In any environment where industrial eye protection is required, contact lenses should not be worn, except under special medical circumstances (in consultation with a qualified medical professional). If individual medical circumstances require that contact lenses be worn in such environments, eye protection must also be used.

How do I identify eye hazards for contact lens wearers?

To ensure the safe use of contact lenses in the work environment, occupational health and safety principles must be applied to identify and control any possible hazards.

The most common hazards to contact lens wearers have been discussed. Quantification of hazards is difficult and a variety of complex approaches have been developed. However, the most useful way of evaluating the risk is to classify it as either acceptable or not acceptable.

If the risks of wearing contact lenses in a particular environment are found to be within acceptable limits, then the only course of action needed is ongoing monitoring of the situation.

If the risks are found to be unacceptable, then further action is required to eliminate existing hazards or to reduce hazards to acceptable levels.

Tips for wearing Contact Lenses at Work.

•Take special care to keep contact lenses clean. Follow the advice of your Optometrist.

•Discuss your work environment and any possible hazards with your eye care specialist.

•Make sure that fellow employees and the employer know that you are wearing contact lenses.

•Be alert for changes to the work process and changes to environmental conditions that may be hazardous to you.

•Keep eye glasses available for unforseen circumstances.

•Wear personal protective equipment whenever required.

•Learn about eye hazards and encourage your employer and joint health and safety committee members to do the same.

Source: http://www.ccohs.ca/oshanswers/prevention/contact_len.html

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