Contact lenses are small, prescription lenses worn directly on the surface of the eye. They are designed to correct refractive errors and support eye health. Similar to regular eyeglasses, contact lenses work by refracting and focusing light to ensure that objects appear clear.

Prescription contact lenses are corrective lenses specifically designed to enhance vision. They can correct various visual impairments, including myopia (nearsightedness), hypermetropia (farsightedness), astigmatism, and presbyopia. These lenses offer a convenient and effective alternative to glasses, providing clear vision while resting directly on the eye.

Cosmetic contact lenses are designed to alter the appearance of the eye, enhancing or changing its colour and look. They are available with or without prescription and, like all contact lenses, carry a similar risk of complications.

Due to these potential risks, even non-prescription (zero-powered) lenses are classified as medical devices. A proper contact lens exam and fitting by an eye care professional are essential before their first use to ensure safe and comfortable wear.

Therapeutic contact lenses are used in the management and treatment of various eye conditions. For instance, a bandage contact lens is often applied to protect the cornea from further irritation by preventing the eyelid from rubbing against a damaged or diseased cornea. These lenses promote healing and provide relief in cases of injury or eye disease.

Binocular vision is the ability to use both eyes simultaneously to process visual information. This allows us to compare input from each eye, improving depth perception, coordinating eye movements, and helping us more accurately judge distance and take in our surroundings.

A glance at the animal kingdom reveals a wide variety of visual systems, each adapted to suit the specific needs of that species. One key feature to observe is the position of the eyes on the head and their relation to each other, which offers valuable insight into how that species uses its vision.

For example, the lighter shaded areas show what can be seen by just one eye, while the darker areas represent the region seen by both eyes at the same time, highlighting the importance of binocular vision in depth perception and spatial awareness.

In humans, most of the visual field is overlapped between both eyes, highlighting how our vision system is designed for both eyes to work together. This is essential for detail perception, smooth navigation, and accurate depth judgment, contributing to better spatial awareness.

However, several issues can disrupt this system from functioning properly, such as:

• Amblyopia
• Strabismus
• Convergence insufficiency
• Reduced binocular processing

Key Ways We Use Visual Information:

Spatial Awareness
Our brain’s ability to accurately construct our perception of the physical environment relies on complex physiological and psychological cues.

Accommodation
Accommodation refers to the tension in the eye’s muscles that adjust the focal length of the lens, allowing us to focus on objects at different distances.

Convergence
When we focus on a nearby object, our eyes slightly point inward, a process known as convergence. This depth cue is effective for close distances (under 10 metres).

Binocular Parallax
Since our eyes are positioned slightly apart, they perceive the world from different angles. This difference in perception is called binocular parallax, which plays a crucial role in depth perception, especially at medium distances.

Monocular Movement Parallax
Even with one eye closed, we can perceive depth by moving our head. Our visual system processes depth by comparing two similar images seen in succession, much like it combines images from both eyes.

Retinal Image Size
When we know the actual size of an object, our brain compares its perceived size to estimate its distance.

Linear Perspective
Looking down a straight road, we see parallel sides converging at the horizon. This effect, known as linear perspective, is a key depth cue, often visible in photographs.

Texture Gradient
The closer we are to an object, the more detail we see in its texture. Smoother textures tend to be interpreted as farther away, especially when spanning near and far distances.

Overlapping
When one object partially blocks another, the blocking object appears closer. The object with the more continuous outline is perceived as nearer.

Aerial Perspective
Distant objects, like mountains on the horizon, appear hazy or bluish due to small particles in the air. The farther away an object, the hazier it looks.

Shades and Shadows
Shadows provide important depth cues. When we know the direction of light, shadows help us judge which object is closer. This principle is often used in 3D computer graphics. Bright objects also tend to appear closer than darker ones.

In most cases, the visual information needed to accurately perceive an environment is present, but not fully processed. Binocular vision and spatial judgment can be trained and improved to enhance everyday skills, sports performance, and overall navigation.

Computer Vision Syndrome (CVS) & Computer Glasses

Eye strain and other symptoms of computer vision syndrome (CVS) aren’t limited to adults. Millions of children use computers daily, whether at home or school, and extended screen time can place significant strain on their eyes. This prolonged exposure may also impact normal vision development in children.

Consideration of proper screen time management and the use of computer glasses can help reduce these risks and protect their eye health.

• Headaches
• Difficulty focusing
• Burning eyes
• Tired or fatigued eyes
• Red eyes
• Double vision
• Eye twitching
• Blurred vision
• Neck and shoulder pain

Do I Still Need Computer Glasses If I Don’t Have CVS Symptoms?
Possibly. Even if you don’t experience symptoms of computer vision syndrome, you may still benefit from computer glasses. Research has shown that computer users without noticeable eye problems can still experience reduced productivity and accuracy, which may improve with proper eyewear.

Computer vision syndrome occurs because our eyes and brain respond differently to characters on a screen compared to printed text. This often leads to eye strain, especially during extended periods of computer use.

How Can I Prevent It?
To reduce the risk of eye strain and CVS, consult an optometrist or ophthalmologist who specialises in computer vision care.

During a computer vision exam, your eye doctor will conduct tests to identify any vision issues that might contribute to CVS. Based on the results, they may recommend computer glasses to help you work more comfortably at your screen. Proper eyewear can go a long way in preventing strain and improving your overall visual comfort.

Computer glasses help reduce the constant refocusing your eyes do when looking at a screen, which eases eye strain. Nearly any frame style can be used for these glasses, making them both practical and customisable.

Since studies suggest that most computer users experience some level of eye discomfort, it’s safe to say that anyone who spends more than a couple of hours on a computer daily could benefit from using computer eyewear.

Do Reading Glasses Offer the Same Protection?
Not really. Reading glasses are typically designed for a reading distance of 14 to 16 inches from your eyes. However, for optimal comfort, your computer screen should be positioned further away, around 20 to 24 inches. For this distance, you’ll likely need a different prescription to reduce eye strain and see clearly.

Does Computer Vision Syndrome (CVS) Impact Productivity?
Yes, it does. Research shows that even minor vision issues can negatively affect productivity and accuracy when working on a computer. Correcting your vision with computer glasses can help improve your performance.

Will Wearing Computer Glasses Make My Eyes Worse?
No, computer glasses won’t harm your eyes. In fact, they can help prevent worsening vision by reducing the strain your eyes experience from focusing for long periods. This is especially true for teenagers, who may be more prone to developing progressive nearsightedness due to focusing fatigue.

We all know that driving at night is more demanding and stressful than driving during the day. While we naturally adjust to these conditions, it’s a fact that the number of road accidents at night is significantly higher than during the day.

This is partly due to the lower lighting levels at night. In response, our pupils enlarge to let in more light, but this can also highlight any small focusing errors, leading to blurry vision. If you notice blurred vision while driving at night, it may be a sign that your current glasses or contact lenses need updating, or that you require an optical correction.

The most common cause of haloes and reflections while driving is a dirty windscreen, both inside and out. Similarly, scratched or dirty spectacle lenses can scatter light, as can condensation on these surfaces.

To minimise these issues, always clean your windscreen and glasses before night driving. Sometimes, reflections on the surface of your glasses can create multiple images of lights at night. If this happens, consider getting lenses with an anti-reflection coating, which can significantly reduce these unwanted visual effects.

Unfortunately, age-related changes in the eye can increase sensitivity to glare while driving at night, especially in older drivers. This is often due to cataracts, which can create a similar effect to looking through a dirty window.

Spectacles won’t fix this problem, so it might be wise to reduce night driving if you’re affected. If oncoming headlights are a problem, try focusing on the left-hand curb as you drive—but don’t forget to slow down!

There’s no solid evidence that amber night or blue light glasses improve vision while driving. In fact, tinted lenses can actually make your vision worse at night. The same goes for tinted windscreens, which is why the Highway Code advises against using any form of tint when driving at night.

• Have your eyes tested regularly
• Always wear your most up-to-date distance glasses or contact lenses
• If possible, keep a spare pair of glasses in your car
• Avoid tinted lenses, but consider getting an anti-reflection coating if needed
• Always keep your windscreen clean, both inside and out

It’s important to include vision care and eye check-ups as part of your child’s routine medical care.

There are different types of eye care professionals, and the terms can sometimes be confusing:

• Ophthalmologists: These are medical doctors who offer comprehensive eye care, including surgery and medication.
• Paediatric Ophthalmologists: These doctors have additional training to specialise in children’s eye problems.
• Optometrists: They provide many of the same services as ophthalmologists but don’t perform surgery. Some optometrists also specialise in treating children’s eye issues.
• Opticians: They fit and adjust spectacles, making sure your child’s glasses fit correctly.

• Newborns should be assessed for general eye health by a paediatrician or family doctor while in the hospital nursery.
• High-risk newborns, such as premature infants, those with a family history of eye problems, or those with visible eye irregularities, should be evaluated by an eye specialist.
• During the first year of life, all infants should undergo routine eye health screenings during their check-ups with a paediatrician or family doctor.
• Around the age of 3½, children should have eye health screenings and visual acuity tests (which measure the sharpness of vision) conducted by their paediatrician or family doctor.
• By age 5, children should have their vision and eye alignment assessed by their paediatrician or family doctor. If they fail either of these tests, they should see an eye specialist.
• After age 5, routine screenings should take place at school and during visits to the primary doctor. If symptoms like squinting or frequent headaches arise, an eye exam is recommended. Teachers often notice when a child is struggling to see clearly in class.
• Children who wear prescription glasses or contact lenses should have annual check-ups with an eye doctor to monitor any changes in their vision.

• Look out for the following signs that may indicate your child is experiencing vision issues:

  • Frequent eye rubbing
  • Extreme sensitivity to light
  • Difficulty focusing
  • Poor visual tracking (trouble following moving objects)
  • Abnormal alignment or movement of the eyes (especially after 6 months of age)
  • Chronic redness of the eyes
  • Persistent tearing
  • A white pupil instead of a black one

  For school-age children, additional signs to watch for include:

  • Inability to see objects clearly at a distance
  • Difficulty reading the blackboard
  • Squinting frequently
  • Struggling to read
  • Sitting too close to the TV

  Keep an eye on your child for any signs of poor vision or crossed eyes. If you notice any issues, it’s important to have your child evaluated by an eye care professional as soon as possible to prevent any long-term problems. Many eye conditions can be corrected if detected early.

• Amblyopia, commonly known as “lazy eye,” is a condition where one eye has poor vision, despite appearing normal. This can occur due to issues such as crossed eyes or a significant difference in refractive error between the two eyes. If left untreated, amblyopia can lead to irreversible vision loss in the affected eye, as the brain may begin to ignore signals from it. The best time to treat amblyopia is as early as possible, ideally before the child turns 8 years old.

  Strabismus refers to the misalignment of the eyes, which may turn inwards, outwards, upwards, or downwards. If one eye is consistently misaligned, amblyopia can develop in that eye as well. Early detection is crucial, as vision can often be restored by patching the properly aligned eye, which encourages the misaligned eye to function. Surgery or specially designed glasses may also help align the eyes.

  Refractive errors occur when the shape of the eye prevents light from focusing correctly, resulting in blurred vision. These errors can also lead to amblyopia. The most common refractive error in school-age children is nearsightedness, but others include:

  • Nearsightedness (myopia): Poor distance vision, typically treated with glasses or contact lenses.
  • Farsightedness (hyperopia): Difficulty seeing nearby objects, also usually corrected with glasses or contact lenses.
  • Astigmatism: An imperfect curvature of the front surface of the eye that causes blurred vision or discomfort, generally treated with glasses.

  Certain eye conditions require immediate attention, such as retinopathy of prematurity, which affects premature babies, and those linked to family history, including:

  • Retinoblastoma: A malignant tumour that typically appears within the first three years of life. The affected eye(s) may exhibit visual loss and a whitish appearance in the pupil.
  • Infantile cataracts: Clouding of the eye’s lens that can occur in newborns.
  • Congenital glaucoma: A rare condition in infants, often inherited, resulting from high pressure in the eye due to incomplete development of the eye drainage canals before birth. This condition can be treated with medication and surgery.
  • Genetic or metabolic diseases: Certain inherited disorders may increase a child’s likelihood of developing retinoblastoma or cataracts, necessitating early eye exams and regular screenings.

  If your child is at risk for any of these conditions, it’s essential to consult your doctor for appropriate care and monitoring.

Yes, children of all ages— including babies—can wear glasses and contact lenses. Here are some tips to consider for kids who wear glasses:

• Let Kids Choose Their Frames: Allowing children to pick their own frames can help them feel more comfortable and confident wearing glasses.
• Opt for Plastic Frames: For children younger than two, plastic frames are the best choice as they are more flexible and durable.
• Spring Hinges for Metal Frames: If older children prefer metal frames, ensure they have spring hinges for added durability.
• Elastic Straps for Toddlers: Attaching an elastic strap to the glasses can help keep them securely in place, especially for active toddlers.
• Consider High-Index Lenses: Kids with severe eye problems may require high-index lenses, which are thinner and lighter than regular plastic lenses.
• Use Polycarbonate Lenses: These lenses are ideal for all kids, particularly those involved in sports. Polycarbonate is a tough, shatterproof thermoplastic that produces thin, lightweight lenses. However, while they are highly impact-resistant, they do scratch more easily than standard plastic lenses.

For babies born with congenital cataracts, surgical removal of the cataracts is often necessary within the first few weeks of life. Some of these infants may wear contact lenses after their surgery.

Around age 10, children may express interest in contact lenses for cosmetic reasons or to enhance their performance in sports. To wear contacts, children need to learn how to insert and remove them properly, adhere to wearing schedules, and maintain good hygiene by cleaning them as recommended by their eye doctor. Many issues related to contact lenses stem from poor habits and inadequate hygiene.

Your eye doctor can provide guidance on the most suitable vision correction options for your child.

Diabetic retinopathy is a condition that affects the blood vessels in the retina, the light-sensitive tissue located at the back of the eye. It is the leading cause of vision loss among individuals with diabetes and is a significant contributor to vision impairment and blindness in working-age adults.

The retina consists of specialized cells known as rods and cones, which line the inner surface of the eye. When light enters the eye, it passes through the lens, which focuses it onto the retina. The cells in the retina then transmit messages about what you see to the optic nerve, which carries this information to the brain. The retina is also nourished by numerous tiny blood vessels that supply oxygen and nutrients essential for its function.