Screen time and blue light

Screen Time & Blue Light – ‘Getting the Blues’

Blue light

Technology has delivered an astounding array of developments over recent decades. Computers have moved from room sized arrays to, quite literally, the palm of our hands and the interface between the device and us, the screen, is becoming the source of greater scrutiny.

In order to deliver better results for clarity and brightness, technology developers have created screens and lighting that produces a ‘whiter’ or ‘cooler’ light. Consequently we are experiencing a somewhat greater level of blue light from our devices than previously and at greater intensities.

While there is evidence that blue light wavelengths are valuable for increasing our attention span and alertness, it seems counterintuitive to want this effect at night when we are preparing for bed. Yet this is the time when many people tuck themselves in to catch up on emails, surf the web or wander through social media. Put in context, we have now started stimulating our brains at the very point when we would traditionally be winding down for sleep.

Screen time

In Australia there has been considerable interest in how blue light works with the human eye[i]. Recent debate has centred on the role of blue light in macular degeneration and damage to the retina with limited results available thus far. Early indications are that, like UV exposure, the effect of blue light on the eye may be cumulative so damage may appear as a result of a lifetime of exposure rather than from brief periods. When considered in the context of extended screen usage in the evenings as well as all day at work then it is possible to see the source of concern among researchers and industry.

Melatonin & sleep

Research from Harvard Medical School has suggested another link between excessive blue light exposure at night and adverse health effects[ii]. By exposing subjects to light it is possible to change the production of melatonin in the body, which in turn can influence the circadian rhythms (or sleep patterns). The Harvard studies indicate that blue light specifically has a greater effect than other wavelengths or even white light. By comparing blue and green light they found that blue light changed sleep patterns by twice as much (3 hours vs 1.5 hours shift in sleep pattern).

While the dose of blue light from a screen pales when compared to natural sources like the sun there is the timing of the exposure to consider, we have shifted our exposure to include all hours of the day and night rather than just daylight hours. In light of this it appears that prudence is the order of the day so the following tips may prove useful:

  • Use features such as “Night Shift” or “f.lux” which change the type of light (also known as temperature) to a warmer light at night.
  • Consider using warm colour light globes.
  • Many lens manufacturers are offering lens coatings that are specifically designed for screen users such as the Solitaire Protect Balance. These coatings can give relief for people using screens for extended periods.

[i]Blue Light Guidelines Coming’, Optometry Australia News, Helen Carter, June 20, 2016

[ii] ‘Blue Light Has A Dark Side’, Harvard Health Letter, September 2, 2015

Facial Measurements & Online Spectacles

Some years ago there was a rush by website developers to offer online spectacles and we often get asked why we don’t have an online spectacle shop as well. The answer is quite simple, one of the most fundamental parts of getting accurate spectacles made is the facial measurements and we can’t get those via an online shop. Our primary concern is the accuracy and suitability of your spectacles so that you maintain good ophthalmic health and functional vision.

In order to make a functional pair of spectacles there are several key components:

  • Prescription
  • Lens design
  • Frame
  • Facial measurements
  • Fitting compensations

No matter how sophisticated the system may be for a website they will never be able to deal with the last two points, most websites claim that they can deal with the frame fitting as well, but this is really only something that can be done ‘face to face’. In fact, even the lens design is nearly impossible to get perfect without having a detailed discussion with the patient, so let’s be frank, all an online seller of spectacles will be able to do is make something that duplicates your prescription without any regard to usage or appropriateness (we’ve checked, and they even have a disclaimer saying that their spectacles are not guaranteed to be usable!).

In order to correctly select and fit a spectacle lens to a frame we need to know the dimensions of the patients face and relative eye positions, and no, that is not just the ‘PD’. There are also heights, vertex distance, tilt, working distance and so on. What they determine, indeed what is most important, is the centre of rotation of the eye. This is vital to position the lens correctly so that the patient does not experience unwanted aberrations. It is also impossible to obtain these various measurements without either a great deal of skill or specialised equipment. None of these measurements are possible via an app and most certainly can’t be obtained in the absence of the frame!

Once this information has been determined the practitioner will make compensations to the measurements to ensure that the lenses present precisely the same powers to the eye as were measured by your Optometrist in the eye test. Patients are often amazed by the large impact that a tilt or shift in centration can have on their perception of the world and it is this role that your practitioner plays almost unseen to the public, the interpretation of the prescription.

This is why many practitioners decline to offer facial measurements to their patients when asked, it is not meant as an insult, rather it is an indicator of their level of concern for your ongoing optical health.

With ever greater advances in lens design these measurements become increasingly vital, in some cases an error of even 1mm will render your lenses effectively useless. Going online means that you may be getting far less than you paid for.

For further information on public policy on this and other issues relating to Optometry please visit the following sites from Optometry Australia


Tulip Time 2016


We’ve been hard at work for Tulip Time 2016. Every year Bowral puts its best foot forward and we decided that we wanted to do something extra special.

Taking old unusable lenses we have been cutting them into tulips and hand tinting themDSC_0288 in our lab.

At Hannaford Eyewear we are proud to be one of only a few practics in Australia that still makes your spectacles on site. It’s just another example of how we bring our expertise to the town we love.

Follow the link below to see video of our team in action or head over to the media page.

Hannaford Eyewear Tulip Time 2016


Southern Highlands Business Awards

The team at Hannaford Eyewear are excited to announce that we are once again finalists in the Southern Highlands Business Awards.

We would like to thank all of our wonderful patients for their support over the years. We couldn’t do it without you!

Business award

Impression Freesign 3


Until the end of September Hannaford Eyewear is offering incredible deals on Impression Freesign 3 Progressive lenses. Over $200 in savings to be had, contact us today to learn more.

UPDATE: Please note that this offer has now ended but we have plenty more amazing value available, contact us now!