So, you got your eyesight tested and found out you need your first pair of glasses. Or you found out you need a stronger pair than the ones you have. You put them on and everything looks crystal clear. But after a few weeks things look blurrier without them than they did before your eye test. What’s going on?

Some people start to wear spectacles for the first time and perceive their vision is “bad” when they take their glasses off. They incorrectly interpret this as the glasses making their vision worse. Fear of this might make them less likely to wear their glasses.

But what they are noticing is how much better the world appears through the glasses. They become less tolerant of a blurry world when they remove them.

Here are some other things you might notice about eyesight and wearing glasses.

Lazy eyes?

Some people sense an increasing reliance on glasses and wonder if their eyes have become “lazy”.

Our eyes work in much the same way as an auto-focus camera. A flexible lens inside each eye is controlled by muscles that let us focus on objects in the distance (such as a footy scoreboard) by relaxing the muscle to flatten the lens. When the muscle contracts it makes the lens steeper and more powerful to see things that are much closer to us (such as a text message).

From the age of about 40, the lens in our eye progressively hardens and loses its ability to change shape. Gradually, we lose our capacity to focus on near objects. This is called “presbyopia” and at the moment there are no treatments for this lens hardening.

Optometrists correct this with prescription glasses that take the load of your natural lens. The lenses allow you to see those up-close images clearly by providing extra refractive power.

Once we are used to seeing clearly, our tolerance for blurry vision will be lower and we will reach for the glasses to see well again.

The wrong glasses?

Wearing old glasses, the wrong prescription (or even someone else’s glasses) won’t allow you to see as well as possible for day-to-day tasks. It could also cause eyestrain and headaches.

Incorrectly prescribed or dispensed prescription glasses can lead to vision impairment in children as their visual system is still in development.

But it is more common for kids to develop long-term vision problems as a result of not wearing glasses when they need them.

By the time children are about 10–12 years of age, wearing incorrect spectacles is less likely to cause their eyes to become lazy or damage vision in the long term, but it is likely to result in blurry or uncomfortable vision during daily wear.

Registered optometrists in Australia are trained to assess refractive error (whether the eye focuses light into the retina) as well as the different aspects of ocular function (including how the eyes work together, change focus, move around to see objects). All of these help us see clearly and comfortably.

What about dirty glasses?

Dirty or scratched glasses can give you the impression your vision is worse than it actually is. Just like a window, the dirtier your glasses are, the more difficult it is to see clearly through them. Cleaning glasses regularly with a microfibre lens cloth will help.

While dirty glasses are not commonly associated with eye infections, some research suggests dirty glasses can harbour bacteria with the remote but theoretical potential to cause eye infection.

To ensure best possible vision, people who wear prescription glasses every day should clean their lenses at least every morning and twice a day where required. Cleaning frames with alcohol wipes can reduce bacterial contamination by 96% – but care should be taken as alcohol can damage some frames, depending on what they are made of.

When should I get my eyes checked?

Regular eye exams, starting just before school age, are important for ocular health. Most prescriptions for corrective glasses expire within two years and contact lens prescriptions often expire after a year. So you’ll need an eye check for a new pair every year or so.

Kids with ocular conditions such as progressive myopia (short-sightedness), strabismus (poor eye alignment), or amblyopia (reduced vision in one eye) will need checks at least every year, but likely more often. Likewise, people over 65 or who have known eye conditions, such as glaucoma, will be recommended more frequent checks.

An online prescription estimator is no substitute for a full eye examination. If you have a valid prescription then you can order glasses online, but you miss out on the ability to check the fit of the frame or to have them adjusted properly. This is particularly important for multifocal lenses where even a millimetre or two of misalignment can cause uncomfortable or blurry vision.

Conditions such as diabetes or high blood pressure, can affect the eyes so regular eye checks can also help flag broader health issues. The vast majority of eye conditions can be treated if caught early, highlighting the importance of regular preventative care.

James Andrew Armitage, Professor of Optometry and Course Director, Deakin University and Nick Hockley, Lecturer in Optometric Clinical Skills, Director Deakin Collaborative Eye Care Clinic, Deakin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Chiropractors in Australia will not be able to perform spinal manipulation on children under the age of two once more, following health concerns from doctors and politicians.

But what is the spinal treatment at the centre of the controversy? Does it work? Is there evidence of harm?

We’re a team of researchers who specialise in evidence-based musculoskeletal health. I (Matt) am a registered chiropractor, Joshua is a registered physiotherapist and Giovanni trained as a physiotherapist.

Here’s what the evidence says.

Remind me, how did this all come about?

A Melbourne-based chiropractor posted a video on social media in 2018 using a spring-loaded device (known as the Activator) to manipulate the spine of a two-week-old baby suspended upside down by the ankles.

The video sparked widespread concerns among the public, medical associations and politicians. It prompted a ban on the procedure in young children. The Victorian health minister commissioned Safer Care Victoria to conduct an independent review of spinal manipulation techniques on children.

Recently, the Chiropractic Board of Australia reinstated chiropractors’ authorisation to perform spinal manipulation on babies under two years old. But this week, it backflipped, following heavy criticism from medical associations and politicians.

What is spinal manipulation?

Spinal manipulation is a treatment used by chiropractors and other health professionals such as doctors, osteopaths and physiotherapists.

It is an umbrella term that includes popular “back cracking” techniques.

It also includes more gentle forms of treatment, such as massage or joint mobilisations. These involve applying pressure to joints without generating a “cracking” sound.

Does spinal manipulation in babies work?

Several international guidelines for health-care professionals recommend spinal manipulation to treat adults with conditions such as back pain and headache as there is an abundance of evidence on the topic. For example, spinal manipulation for back pain is supported by data from nearly 10,000 adults.

For children, it’s a different story. Safer Care Victoria’s 2019 review of spinal manipulation found very few studies testing whether this treatment was safe and effective in children.

Studies were generally small and were of poor quality. Some of those small, poor-quality studies, suggest spinal manipulation provides a very small benefit for back pain, colic and potentially bedwetting – some common reasons for parents to take their child to see a chiropractor. But overall, the review found the overall body of evidence was very poor.

However, for most other children’s conditions chiropractors treat – such as headache, asthma, otitis media (a type of ear infection), cerebral palsy, hyperactivity and torticollis (“twisted neck”) – there did not appear to be a benefit.

The number of studies investigating the effectiveness of spinal manipulation on babies under two years of age was even smaller.

There was one high-quality study and two small, poor quality studies. These did not show an appreciable benefit of spinal manipulation on colic, otitis media with effusion (known as glue ear) or twisted neck in babies.

Is spinal manipulation on babies safe?

In terms of safety, most studies in the review found serious complications were extremely rare. The review noted one baby or child dying (a report from Germany in 2001 after spinal manipulation by a physiotherapist). The most common complications were mild in nature such as increased crying and soreness.

However, because studies were very small, they cannot tell us anything about the safety of spinal manipulation in a reliable way. Studies that are designed to properly investigate if a treatment is safe typically include thousands of patients. And these studies have not yet been done.

Why do people see chiropractors?

Safer Care Victoria also conducted surveys with more than 20,000 people living in Australia who had taken their children under 12 years old to a chiropractor in the past ten years.

Nearly three-quarters said that was for treatment of a child aged two years or younger.

Nearly all people surveyed reported a positive experience when they took their child to a chiropractor and reported that their child’s condition improved with chiropractic care. Only a small number of people (0.3%) reported a negative experience, and this was mostly related to cost of treatment, lack of improvement in their child’s condition, excessive use of x-rays, and perceived pressure to avoid medications.

Many of the respondents had also consulted their GP or maternity/child health nurse.

What now for spinal manipulation in children?

At the request of state and federal ministers, the Chiropractic Board of Australia confirmed that spinal manipulation on babies under two years old will continue to be banned until it discusses the issue further with health ministers.

Many chiropractors believe this is unfair, especially considering the strong consumer support for chiropractic care outlined in the Safer Care Victoria report, and the rarity of serious reported harms in children.

Others believe that in the absence of evidence of benefit and uncertainty around whether spinal manipulation is safe in children and babies, the precautionary principle should apply and children and babies should not receive spinal manipulation.

Ultimately, high quality research is urgently needed to better understand whether spinal manipulation is beneficial for the range of conditions chiropractors provide it for, and whether the benefit outweighs the extremely small chance of a serious complication.

This will help parents make an informed choice about health care for their child.

Matt Fernandez, Senior lecturer and researcher in chiropractic, CQUniversity Australia; Giovanni E. Ferreira, NHMRC Emerging Leader Research Fellow, Institute of Musculoskeletal Health, University of Sydney, and Joshua Zadro, NHMRC Emerging Leader Research Fellow, Sydney Musculoskeletal Health, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.