拍摄者 Pascal Chanel不飞溅

Tearing

Tears are needed to keep the eye’s front surface healthy and to maintain clear vision. It is
common to temporarily produce excess tears when you are emotional, laughing, coughing,
vomiting, experiencing strong taste sensations, or yawning.

Types of Tears

photo credit: allaboutvision.com

Different types of tearing consist of basal tears, emotional tears, and reflex tears. Basal tears are your basic functional tears. They are released in tiny amounts to lubricate your ocular surface and keep it clear of any dust. These are vital for good vision and comfort. Emotional tears are triggered by strong feelings such as joy or sadness. Reflex tears result from irritation in the eye by foreign bodies, or from the presence of irritant substances in the environment. They can also occur with bright lights hot or peppery stimuli to the tongue and mouth, when we yawn, cough or even vomit. These types of tears are released in larger amounts than basal tears. Their goal is to protect one’s eye.

How can I have Dry Eyes if my eyes are so watery?

The two common causes of watery eyes are blocked tears ducts and excessive production of tears. The common cause of excessive production of tears is dry eye syndrome. This occurs due to the glands around our lid margins not producing enough oil resulting the tears drying up very quick. This lack of lubrication results in our eyes producing an abundance of tears to compensate.

拍摄者 Nick Fewings不飞溅

It is often said that eating carrots will help you see better due to the high amounts of vitamin A. Although vitamin A plays an important role in our vision, it is unable to improve the quality of our vision. Vitamin A is able to prevent diseases such as macular degeneration which can result in severe vision loss if left untreated.

What is Vitamin A?

Vitamin A is derived from beta-carotene which acts as an antioxidant. This is essential in protecting our cells against heart disease, cancer, and many other diseases. Deficiency in vitamin A is the leading cause of preventable blindness in children across the world. Due to this, it is important to have some type of source for vitamin A such as carrots, eggs, spinach, or broccoli.

What does Vitamin A do for our eyes?

Vitamin A allows us to produce pigments needed in-order for the retina to function properly. Without these pigments, it would become much more difficult to see in the dark leading to eventual night blindness. Lack of vitamin A can also lead to a lack of nourishment to the cornea resulting in the eyes not producing enough moisture to keep the cornea lubricated. This can lead to our eyes becoming dry which can result in severe complications such as ulceration of the cornea and eventual blindness if not appropriately treated.

Image by Freepik

While it is untrue that reading in the dark will permanently damage your eyes it can cause shorter term issues. You may have to strain harder which can lead to headaches, irritated eyes, general eye fatigue. If this is coupled with other existing issues you may also experience blurry vision or even double vision temporarily. The extra strain and need to focus may also prevent you from blinking as often, leading to dry eye symptoms.

拍摄者 bruce mars不飞溅

Presbyopia is the gradual loss of your eyes’ ability to focus up close. This tends to start around your early 40s and progresses until around the age of 65. You may notice starting to hold reading material further away to keep it clear, blurry vision at previously normal reading distance, eyestrain or headaches after extended periods of reading.

Managing presbyopia

Depending on your health, lifestyle and preferences, your eye care specialist may suggest any of the following methods to correct presbyopia:

  • Eyeglasses in the form of readers, bifocals, progressives, etc.
  • Contact lenses, typically multifocal or monovision
  • Surgeries
  • Eye drops such as Vuity

Can I prevent presbyopia?

You can’t prevent presbyopia since it’s a part of the natural aging process. You can, however, take steps to protect your eye health. This includes:

  • Wearing sunglasses to shield your eyes from harmful ultraviolet (UV) rays.
  • Eat foods rich in nutrients that promote eye health, including vitamin A, vitamin C, vitamin E and lutein, and Omega-3s
  • Improve lighting in work areas
  • Increase font and change contrast in smart phones or computer devices etc.
拍摄者 Lensabl不飞溅

If I’m careful with cleaning, can I wear my dailies for more than 1 day?

Daily disposables are thinner and are made of a material that is not made to resist bacteria and buildup. So, if you try to clean or disinfect these thin lenses you may actually create breaks instead, further increasing infection risk. Using a compatible brand of soft contact lens rewetting drops to hydrate your daily disposables for comfort is acceptable.

What happens if I wear dailies for more than 1 day?

Wearing daily disposable contact lenses more than once puts you at risk for discomfort, dryness, corneal ulceration/scarring, and eye infections.

Differences between Dailies, Bi-weeklies, and Monthlies

Dailies are worn only for one day and discarded when you remove them, these are typically very thin and have a high water content. Natural deposits from your eyes build up easily on their surface, and they cannot be reused. This could mean more convenience but also, depending on how often you replace them, more costly.

Monthly or bi-weekly contact lenses are thicker than daily disposables. The thicker composition makes them more durable and long-lasting, and they are usually more resistant to drying out. However, they must be disinfected regularly in order to ensure healthy wearing.

Photo credit: iris.ca

In the case of nearsightedness, farsightedness, astigmatism, or presbyopia refractive surgery can help either reduce or eliminate the need for glasses/contacts and improve vision. Good candidates include:

  • Patients with stable unchanging refractive errors
  • Patients with thick healthy corneas and good overall ocular health
  • Patients whose lifestyle/expectations match the surgery they choose

Candidates may have limited options or should avoid refractive surgery if they have:

  • thin corneas
  • severe dry eye
  • extreme levels of myopia, hyperopia, or astigmatism
  • corneal scars
  • cataracts
  • history of eye infections or an active eye infection
  • diabetes
  • glaucoma

What to expect with refractive eye surgery

Before your surgery, your optometrist will:

  • Discuss options and expectations associated with the different types of refractive eye surgery
  • Test your vision
  • Measure the surface and thickness of your cornea
  • Double check if any other existing conditions may complicate or prevent a successful outcome

During your surgery, your doctor will:

  • Instill numbing eye drops
  • Instill devices around your eyelids to prevent blinking
  • Have the patient will stare at a target light to prevent from moving
  • Clicking sounds, duration, other details may vary between different types of surgeries

After your surgery, you will:

  • Use a see through shield to protect your eye while it heals for a few days
  • Apply eye drops to reduce dryness and promote healing
  • Experience varying amounts of scratchy/burning sensations temporarily

Be sure to discuss with your eye care provider about the varying types of refractive surgery options and if they are right for you. Some of these include: LASIK, PRK, ICL, LRI, SMILE etc.

photo credit: Unsplash/pawelskor

Your visual field refers to the area in which you can see objects in all directions as you focus on a single central point. This test of your peripheral vision is simple, painless, and vital in diagnosing and tracking the progress of health conditions.

Are there different types of Visual Fields?

Confrontational Visual Field Test: The patient looks at an object in front of them with one eye covered. While looking at this object the patient will be asked how many fingers they see the doctor holding up in the patient’s periphery.

photo credit: morancore.utah.edu

Automated static perimetry test: The patient looks in the center of a bowl-shaped instrument called a perimeter. Lenses are placed in front of the patient’s tested eye while the other is covered with an eye patch. While looking at the center target, several flashes of light will appear in the patient’s periphery at which point they will use a clicker to indicate when they see them.

photo credit: healthjade.net

Kinetic visual field test: Similar to above but now moving light targets are used instead of blinking lights.

Who needs a Visual Field Test?

Visual fields can be helpful in diagnosing, treatment plans for, and monitoring various conditions such
as:

  • 青光眼
  • Multiple sclerosis
  • Thyroid eye disease
  • Strokes
  • Finding blind spots (scotomas)
  • 糖尿病
  • 高血压

Depending on your situation you may be recommended to take a visual field test again in a few weeks, a
few months, or a year.

It’s not the most comfortable experience, but…

拍摄者 Mārtiņš Zemlickis不飞溅

Dilation is a crucial component of your eye exam. Dilating drops enlarge your pupils to allow more light to enter the eye, giving the doctor a better view of the interior and back of your eye. Think of it as looking through a keyhole – the larger and wider the keyhole, the more you can see into the room behind the door.

Why is dilation important?

  1. It enables your optometrist to more accurately determine your prescription by unmasking the effect of accommodation.
  2. It helps to identify eye conditions in children, such as amblyopia (lazy eye).
  3. It helps detect retinal conditions, glaucoma, and other neurological conditions
拍摄者 v2osk不飞溅

If it’s so important, why isn’t it done in every eye exam?

Although it is recommended for everyone, dilation is not absolutely necessary for all patients and situations. Dilation can cause blurry near vision and light sensitivity for several hours after the drops are applied. To determine if dilation is needed and appropriate, your optometrist considers several factors:

  1. Age. The risk of eye diseases increases with age, so dilation is highly recommended for adults/seniors. In children, it helps to determine a more accurate prescription that is not masked by their accommodation system.
  2. Ocular history/ Family history. Having a history of eye diseases can predict your risk for developing certain conditions. Genetics plays a role in many ocular diseases.
  3. Overall health. Diabetes, high blood pressure, and other systemic conditions increase the likelihood of developing eye problems.
  4. Presenting symptoms. Symptoms that draw patients into the exam room may warrant a dilated exam. Flashes, floaters, or curtain veil over vision warrant immediate dilation, as they can be a sign of a serious condition.
Photo credit: allaboutvision.com

Uveitis is inflammation inside your eye that usually occurs when your immune system fights an infection. It can also happen when your immune system attacks healthy tissue in your eye. Uveitis affects the middle layer of the eye, called the Uvea, resulting in white blood cells and proteins leaking. It can affect one eye or both eyes. Uveitis can affect anyone, but it is most common in people aged 20 to 60.

What are the symptoms of uveitis?

  • Blurry vision
  • Decreased vision
  • Eye pain
  • Red eyes
  • 对光敏感
  • Floaters

There are different types of uveitis.

  1. Anterior Uveitis: affects the iris (colored part of the eye) and is the most common type that affects the front of the eye
  2. Intermediate Uveitis: affects the middle of the eye
  3. Posterior Uveitis: affects the back of the eye
  4. Panuveitis: affects all parts of the eye

What causes uveitis?

The cause of uveitis is not always known. Infections, systemic inflammatory diseases, or an eye injury can all cause uveitis. Smoking cigarettes can increase the risk of uveitis.

How is uveitis treated?

Your optometrist will most likely prescribe two eye drops: a steroid to reduce inflammation, and an eye drop to dilate the pupil to help with the pain and swelling. Uveitis can lead to permanent vision loss; therefore, early diagnosis and treatment are essential to prevent complications and preserve vision.

Many people have experienced styes or have at least heard of it. But what really is a stye? How can we prevent or treat them?

Photo credit: Cleveland Clinic

A stye is a bacterial infection which involves one or a few of the glands at the base of your eyelashes. Often, it resembles a boil or a pimple, it may have a white head and be tender to the touch. Styes can be caused by buildup of Meibomian gland secretions or be idiopathic in nature (unknown cause). In rare worst-case scenarios, recurrent styes in the same spot can be a sign of sebaceous gland carcinomas.

It’s important to maintain good eyelid hygiene by using eyelid cleansers and warm compresses daily. This not only helps to prevent styes, but also alleviates symptoms related to dry eye and eyelash mites.

With styes, patients typically notice pain and discomfort that disappears within a few days. However, more serious cases can develop into pre-septal cellulitis with progressively worsening symptoms and require antibiotics.

Warm compresses help to speed up recovery and relieve discomfort, but if you don’t see improvements after 48 hours, you’ll want to contact your optometrist.