SMOKING vs. VAPING
 

The effects of smoking and its connection to many significant health conditions are well-documented. Perhaps less well known is the impact smoking has on eye health and vision. Not only does smoking damage parts of the eye critical for maintaining clear vision, it also increases the risk for the development of eye diseases such as cataracts, macular degeneration, diabetic retinopathy and dry eye. Vaping and e-cigarettes have become a popular alternative to smoking, and while the research on the impact of vaping is not as extensive as tobacco studies, the results so far indicate that it, too, has damaging effects on both general and eye health.

VISION PROBLEMS CAUSED BY SMOKING

DRY EYE

Cigarettes contain thousands of chemicals, including many irritants that can leave the eyes red, burning, or watery. Cigarette smoke breaks down the lipid layer of the tear film that acts as a barrier against the environment, resulting in dry eye, not only for the smoker but for others exposed to the second-hand smoke. While dry eye does not cause permanent damage, it can be uncomfortable, particularly for contact lens wearers.

MACULAR DEGENERATION

Smokers are more likely to develop damage to their retinas, including age-related macular degeneration (AMD) which causes irreversible damage to the macula, resulting in a loss of central vision and the ability to discern fine details. This severely impacts reading, driving, facial recognition and many daily activities. As well as reduced blood flow to the retina, smokers have been found to have lower levels of the antioxidants lutein and zeaxanthin which protect the macula from ultraviolet radiation, a further risk factor for AMD.

CATARACT

Cataract formation is a natural consequence of aging for many people, but smoking can double the risk of cataracts at an earlier age. Smoking increases the number of highly reactive, unstable free radicals which cause fat and protein deposits to form on the eye’s lens, leading to the development of cataracts.

GLAUCOMA

Smokers are at a higher risk of developing glaucoma by producing free radicals that damage the fibres of the optic nerve which carries visual messages to the brain. This damage can eventually lead to irreversible vision loss.

DIABETIC RETINOPATHY

One of the complications of diabetes is diabetic retinopathy, progressive damage to the tiny blood vessels in the eye which can lead to vision loss if not detected and treated early. Smoking increases the risk of developing diabetes and may speed up the progression of diabetic retinopathy.

UVEITIS

Uveitis is inflammation of the central layer of the eye, causing redness, pain, blurry vision and damage to the iris and retina. Smoking more than doubles the risk of developing uveitis.

COLOUR VISION

Research has shown that some problems with colour and contrast vision may be a consequence of heavy smoking and chronic exposure to the chemicals in cigarettes.

“PASSIVE” SMOKING

Passive smoking, or exposure to second-hand smoke, is a concern for the eye health of children, who have a higher risk of allergic conjunctivitis and the development of eye problems later in life.

EFFECTS OF VAPING ON THE EYES

By providing nicotine through a heated liquid composed of flavouring and other chemicals rather than tobacco, vaping and e-cigarettes are viewed as a healthier replacement for smoking cigarettes. Research generally accepts that while vaping can harm the lungs and other bodily systems, its impact is much less than tobacco smoking. However, a 2019 study into the long-term health effects of vaping found that people using e-cigarettes had a higher risk of respiratory disease than people who never smoked. Vaping may damage the lungs, release free radicals into the body and weaken the immune system. E-cigarettes can cause oxidative stress, a key factor in the development of chronic diseases, as well as cataracts and glaucoma.

Recent studies indicate that vaping has a negative impact on the eyes and that the toxins in e-cigarettes could damage vision. With constant vaping, ingredients like propylene glycol can produce cell-damaging free radicals that may weaken the fluid layer covering the surface of the eye, leading to or worsening dry eye symptoms. One study on tear function suggested that “vaping is not kind on your eyes” after finding lower quality tear film and severe dry eye in people who used vaping products. A study by the University of California found that current vapers were 34% more likely to suffer from visual impairments compared to those who had never tried vaping. While there is no definitive proof that vaping causes visual impairment it does parallel earlier studies linking smoking to eye problems.

Compared to cigarette smoking vaping is a relatively recent activity. While some health authorities believe that vaping is safer than smoking, others feel that this is not necessarily the case and vaping is not risk-free. The chemicals in vaping may be harmful, but on a significantly lower level than tobacco, indicating that they carry less of a health risk than cigarettes. It is not clear whether vaping causes the same eye health concerns as regular cigarettes, but some doctors even suggest that the vision health risks of vaping may be up to four times greater than smoking regular cigarettes, though there have not been any long-term studies to prove this.

It is clear that opinions are divided and there is no conclusive evidence on the lasting effects of vaping versus smoking on eye health. With the proven correlation between regular cigarette smoking and various eye diseases, it is likely that links will also be found with vaping and e-cigarettes. Further investigation is needed for a deeper understanding of the effect of e-cigarettes on the eyes.

MILESTONES OF VISION DEVELOPMENT

The visual system is the most complex sensory system in the human body, but is the least mature at birth, constantly changing and evolving as the child grows and develops. Although babies are born with the structures for sight, they need to learn to use them over time. While having a basic timeline for vision development is a helpful guide for parents to know what to expect at certain ages, it is important to recognise that children reach their developmental milestones at their own pace, and that some stages may overlap.

In utero, the baby’s eyes begin growing at about week 4 of pregnancy. Although he can perceive light at about week 16, the eyelids remain closed until 26 weeks. Visual development begins the moment the baby is born and develops rapidly. At birth the world appears fuzzy but will go from blurry to bright in a few months. Some new-borns look directly at a face after birth, while others keep their eyes tightly shut.

BIRTH TO ONE MONTH

At first all the baby will be able to see is the distance from the caregiver’s arms to their face, about the distance from his face to the face of the person feeding him. By two to three weeks, he will begin to focus on faces for a few seconds. As he focuses for longer, he will begin to make eye contact. The baby sees only in black and white, and shades of grey because the nerve cells in the brain and retina are not yet fully developed. His eyes are not very sensitive to light, so his sleep will not be disturbed if he is in a light room.

Stimulate the baby’s vision by talking to him, smiling at him and placing bold-pattern toys in front of him. He may begin to look at objects and faces on either side of him by turning his head from side to side. He won’t be able to track objects without moving his head until two to four months. Although babies cry, they do not produce tears until the tear glands develop.

TWO TO THREE MONTHS

Although his vison is still fairly blurry, the baby will begin to recognise familiar faces and respond to smiles with a smile of his own. He is starting to notice different colours. Baby’s hands and feet are fascinating to him as he stares at them intently. He becomes easily distracted by interesting objects and begins to reach for things as hand-eye coordination starts to emerge. The eyes are beginning to move independently of the head as he tracks moving objects.

For the first two months of life an infant’s eyes are not well coordinated and may cross or wander. This will usually go away, but if it continues, or if one eye is constantly turned in or out, the baby should be seen by a medical specialist.

THREE TO SIX MONTHS

By six months, the eyes are working together effectively, and the baby is seeing the world in three dimensions. He is able to reach for and grasp objects more accurately. Colour vision has improved, and he may be showing colour preferences. The baby is now able to move his gaze and track objects without having to move his head. He watches toys falling or rolling away.

Play peek-a-boo or hide toys and then reveal them to develop visual memory. Encourage his visual attention by presenting interesting colourful objects, including noise-making toys that enhance listening and strengthen the connection between vision and hearing. A baby is never too young to be introduced to books – choose books with bright simple pictures of familiar objects.

SIX TO TWELVE MONTHS

During this period rapid development takes place in all areas as the baby learns to sit, crawl and explore his world. Vision becomes more refined and becomes coordinated with body movements. The baby will be able to judge distances with more accuracy and will attempt to reach something of interest to him a short distance away. He notices small objects and is able to manipulate them more easily. He enjoys looking at his reflection in the mirror. By the end of his first year the baby has good colour vision, differentiates between near and far, recognises pictures and shows sustained visual interest.

Provide toys that can be pushed or pulled, as well as simple building toys and toys that can be taken apart and fitted together, to enhance hand-eye coordination and encourage visual perceptual skills such as discrimination between sizes and shapes.

Toddlers continue to refine their visual skills as they explore and learn about their visual world. During their preschool years, pre-reading and pre-writing skills develop, and by the time the child enters school he should be ready to face the demands of learning. He should have clear and comfortable vision and be able to change his focus from near to far quickly, smoothly and accurately. He should have mastered the necessary visual skills to facilitate success in the classroom. These include visual attention, discrimination, memory, sequencing, association and hand-eye coordination.

Parents play a vital role in their child’s visual health and development from birth right up to puberty. Provide age-appropriate opportunities for stimulation and enhancement of visual skills and be aware of signs that may indicate a vision problem. If there is a problem, the earlier it is detected and treated, the better the chances for a good outcome.

EYE-MAZING!
 

The human eye provides us with the ability to experience the world in ways that our other senses cannot. The only organ more complex than the eye is the brain which processes and interprets the information gathered by the eyes.

INTERESTING PERSPECTIVE

Because the cornea at the front of the eye is curved, it bends the light that enters the eye, and the image is focused upside down and backwards on the retina. The brain interprets the image and reorients it so that we perceive it right way up. Having two eyes gives us depth perception. The brain computes distances by comparing the different images from each eye.

PROTECTIVE FEATURES

The eye is one of our most fragile organs which is protected by the skull and facial features. The eye socket is hollow and depressed into the skull protecting half the eye within bone. 80% of the human eye is made of a firm jelly-like fluid called vitreous humour that is vital to eye health and function. This clear, colourless substance fills the space between the lens and the retina, maintaining the eye’s shape and keeping the fragile retina in place.

The eyelids shield the eye from light and particles and the eyebrows divert sweat from the eyes. Eyelashes create a filter for dust and other particles and also act as a sensor, triggering the eyelid to close when necessary. The lifespan of an average eyelash is 5 months, while the rest of the hair lasts 2-4 years.

WE CAN’T SEE IT ALL

In the area where the optic nerve exits the eye through the retina, there are no photoreceptors, so no images are detected. We seldom notice this small blind spot, and experts are unsure why. One theory is that the brain fills in the missing information using visual cues in the environment, the other is that the overlapping vision of the two eyes fills in the gap.

TRUE COLOURS

It has been suggested that we can distinguish as many as 10 million colours. The eyes contain 7 million cones which help us see colour and detail and 100 million rods which help us to see better in the dark. All colours visible to humans are made up of combinations of red, yellow and blue which are the only three colours detected by the cone cells. The brain combines these into a rainbow of colours of different shades and hues.

Humans are able to see more shades of green than any other colour. Males are more likely than females to be colour-blind.

EYE COLOUR

Approximately 79% of the world’s population have brown eyes. The next most common eye colour is blue at 8-10%, and the following is amber or hazel eyes at 5%. In spite of being common in some countries, only an estimated 2% of the world’s population have green eyes, making them rare overall. Other rare eye colours include red, violet, and grey.

A small number of people have two different eye colours, a condition called heterochromia. It is thought that blue and green eyes are more sensitive to light than brown eyes, and that brown eyes are more susceptible to cataracts.

Experts agree that everyone, regardless of eye colour, should protect their eyes from the sun.

RED EYE

The “red-eye” effect in photographs occurs when the light of a camera flash or other bright light source is reflected back at the camera.

The reflected light illuminates the blood vessels at the back of the eye, which produces the red colour we see in photos.

On the topic of photographs, if the human eye were a digital camera, it would have 576 megapixels!

EYE-DENTIFICATION

Like a fingerprint, the iris of the eye is unique to each individual. Unlike fingerprints, the iris in each of our eyes is different. The iris has over 256 unique characteristics, compared to fingerprints which have about 40. This makes the iris scan for biometric systems more secure than fingerprints.

BLINK! BLINK!

Blinking removes dirt and lubricates the eye with tears. Each blink brings nutrients to the surface of the eye, keeping it healthy. Scientists have estimated that we blink between 15 and 20 times per minute, 20,000 and 30,000 times per day on average. Each blink lasts just two-tenths of a second, adding up to approximately 1.5 hours per day. We tend to blink less often when we are staring at a digital screen for extended periods, often leading to discomfort.

COMPUTER VISION SYNDROME

Studies suggest that 50% to 90% of people who work at a computer screen show symptoms of computer vision syndrome, which is a range of issues relating to eye strain from too much exposure to screens. Using a screen forces the eyes to constantly focus and refocus, the brightness and glare also make the eyes work harder, and over time this repetitive strain can take a toll on the eye muscles. The 20-20-20 rule is useful – look at something twenty feet away for twenty seconds every twenty minutes. As well as being a reminder to take regular breaks, this generally helps alleviate or prevent eye strain.

RABBITS DON’T WEAR GLASSES!

Are carrots good for eye health?

While vegetables like carrots are rich in beta-carotene and are a healthy addition to your diet, they are not the only foods that have specific benefits for the eyes.

For eye health, eat oily fish and green vegetables that contain lutein, zeaxanthin and meso-zeaxanthin, which support the eye’s protective mechanisms. Lutein and zeaxanthin occur naturally in foods like spinach, kale and other leafy greens, while meso-zeaxanthin can be found in certain fish.

A LOOK AT YOUR NEW-BORN

At birth a baby’s eyes may appear grey or blue. Depending on the amount of melanin in the iris, as well as genetic and other factors, changes to the colour of the eyes will be noticed over a period of six months to one year. New-borns have blurry vision for the first few months, but they do focus on faces. It takes about four months for a baby to fully see colours and distant objects. Although they cry, new-borns don’t produce tears until the tear glands have developed between the ages of two weeks and two months.

INTERESTING EYE-OPENERS

The eyes focus on 50 different objects every second.

The older we get, the less tears we produce.

Contrary to popular belief, you can sneeze with your eyes open.

About 80% of the world’s vision problems can be solved with proper treatments.

The cornea of the shark is the most similar to the human cornea and has been used in human surgery.

Eye tests can detect health conditions. The retina is said to be a good predictor of the health of blood vessels throughout the body.

The eyes are a window to your health, so take good care of them. Follow an eye-healthy diet, exercise regularly, protect them from the sun and environmental hazards, and have regular eye examinations.

DIFFERENT LENS COATINGS FOR DIFFERENT VISUAL NEEDS

Everyone has different visual needs. With the advances in technology and continued improvements in lens coatings, it is possible to cater for each person’s needs and lifestyle. A lens coating is a treatment that is added to glasses to enhance their performance, appearance, durability and longevity, while also providing protection for both your lenses and your eyes. There are many different types of coatings, each with their own benefits.

CAN COATINGS BE ADDED TO ALL LENSES?

Lens coatings can be applied to single vision, bifocal and progressive lenses.

WHICH COATING WILL PROVIDE THE BEST PROTECTION FOR MY LENSES?

To protect your glasses and your vision, a scratch-resistant coating is highly recommended and is essential for children’s glasses. Scratched lenses interfere with the clarity of vision, often leading to eye strain or headaches. Once a lens is scratched it needs to be replaced, as buffing out the scratches or resurfacing the lens changes the curvature and prescription.

While no lenses are completely scratch proof, this coating makes them more resistant to scratches which prolongs their life.

For added protection, store your glasses in a hard case and clean them with a microfibre cloth. Many lenses contain a built-in scratch-resistant or “hard coat”, usually with a warranty included.

IS THERE A COATING THAT CAN PROTECT MY EYES?

Over time, exposure to the ultraviolet rays from the sun can increase the risk of developing eye conditions such as cataracts and macular degeneration. Ultraviolet (UV) coating shields the eyes against these harmful rays as long as it provides 99 – 100% protection.

WHAT IS THE BENEFIT OF AN ANTI-REFLECTION COATING?

As one of the most popular lens treatments, an anti-reflective coating reduces glare and halos by blocking reflected light and allowing more light through the lenses making vision clearer. It is generally applied to the back and front surfaces of the lenses. It is particularly beneficial for night driving when the reflections and halos from streetlights and oncoming vehicles can cause discomfort and eye strain.

The aesthetic of the lenses is improved so that they appear almost invisible allowing people to focus on your eyes rather than being distracted by reflections from your glasses.

Anti-reflection lenses may show smudges more readily than uncoated lenses so should be cleaned regularly with a soft microfibre cleaning cloth.

CAN I AVOID THE NEED FOR SEPARATE GLASSES FOR INDOORS AND OUTDOORS?

Photochromic or Transition lenses, although not strictly a coating, offer the best of both worlds. They automatically change from clear to dark when they come into contact with UV rays, and they have 100% UVA and UVB protection. They also help to reduce blue light emitted by the sun and electronic devices and screens. Not all photochromic lenses are suitable for driving as they may not become dark enough.

IS IT NECESSARY TO HAVE A BLUE LIGHT COATING?

There are different opinions on blue light and its effects on the eyes and the body. Blue light glasses are sometimes recommended for anyone who spends a significant amount of time in front of digital devices. It has been suggested that this lens coating helps to reduce the blue light entering the eyes, resulting in less eye strain and fatigue, better contrast and improved visual comfort.

ARE THERE LENS MATERIALS OR COATINGS THAT ARE EFFECTIVE AGAINST GLARE?

Glare can be mildly irritating, but it can also be dangerous at certain angles, obstructing vision.

Polarised lenses have a built-in filter that blocks horizontal light waves to minimise glare in hazy conditions or reflected off surfaces such as water, wet roads and the bonnet of a car. They reduce eye strain and deepen contrast, creating a better perception of colour, as well as offering 100% UVA and UVB protection.

WHAT IS THE BEST WAY TO CLEAN GLASSES WITHOUT DAMAGING THE LENSES?

It is essential to look after your coated lenses by cleaning them properly and regularly. Avoid using hot water, alcohol, concentrated or abrasive substances to clean coated glasses lenses as this can wear the coating off as well as damage the frames of your glasses. Tissues or the corner of a shirt are abrasive and can scratch the lenses. Use a recommended lens cleaner and a soft microfibre cloth to care for your lenses and extend their life.

ARE LENS COATINGS WORTH THE EXTRA EXPENSE?

Glasses are an expensive item. While some coatings may be included in the price of your prescription, others are add-ons that will cost extra and may not be covered by your medical aid. Speak to your optometrist about getting the most out of lens coatings and achieving the best vision possible by applying the coatings that meet your unique vision and lifestyle needs.

COULD YOUR EYES BE CAUSING YOUR DIZZINESS?

Vision problems such as eye strain can cause dizziness and balance problems.

Balance is a complex task involving the interaction of three systems which work as a team to help us orient ourselves in space and keep us moving easily through our world. The vestibular system in the inner ear informs the brain about the head’s position, motion and orientation in space. The proprioceptive system provides sensory feedback from muscles and joints about the body’s position and motion. The eyes and their movement send information to the brain about the body’s alignment and position in relation to its environment. The visual system helps regulate the other systems involved in maintaining balance. Any defect in the visual system or the healthy functioning of one of the other systems can lead to dizziness or a balance disorder.

The strong connection between the eyes and the vestibular system means that eye problems negatively affect balance. Vision plays an important role in calibrating the vestibular system through the vestibulo-ocular reflex which stabilises the gaze while the head and body are in motion. A number of visual problems can cause dizziness and balance problems. While some of these are purely visual disturbances, others may be associated with other disorders. Conditions that may cause dizziness include eye misalignment, eye muscle weakness, stroke, head injury and incorrect spectacle or contact lens prescriptions.

In many cases, eye-related dizziness is due to binocular vision problems, the inability of the eyes to work together. When a person’s eyes are misaligned, the eye muscles strain to focus and provide the brain with unified and clear images. This may lead to eye strain, dizziness, disorientation, neck strain and headaches. Any visual misalignment, no matter how small or subtle, puts a great deal of stress and strain on the eye muscles, causing them to become tired and overworked.

Other visual conditions that may cause dizziness include nystagmus (involuntary uncontrolled jerky eye movements), strabismus or ‘squint’ (the eyes do not look in the same direction at the same time), amblyopia or ‘lazy eye’, and vertical heterophoria (one eye slightly higher than the other).

Typical symptoms of vision-related dizziness and balance problems include a spinning sensation, unsteady walking, vertigo, lightedheadedness, blurred vision, disorientation, nausea, anxiety, headache, sensitivity to light and double vision. Some people experience all of these symptoms, while others experience only a few. While occasional dizziness is not a cause for concern, frequent experiences of dizziness and loss of balance should be investigated by a medical professional.