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Category: Ocular Health

Posted on by Dr. Melody Tong

What does my eye prescription mean?

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Eyeglass and contact lenses prescriptions can contain components and abbreviations that may be harder to decipher. Here are some of the common abbreviations and what they mean:

  • OD: or oculus dexter refers to your right eye
  • OS: or oculus sinister refers to your left eye
  • SPH: is the sphere and refers to the lens power required to help correct your vision. A (-) negative
    indicates nearsightedness and (+) positive indicates farsightedness
  • CYL: is the cylinder and refers to how much astigmatism you have if any. Astigmatism is caused
    by a cornea or lens that has a different shape than normal and multiple focal points.
    Astigmatism is very common.
  • AXIS: a number between 1 and 180, indicates exactly where the astigmatism appears on your
    eye
  • ADD: stands for the additional lens power needed to make it easier for you to read. This is seen
    on prescriptions for reading glasses or the lower portion of bifocal/progressive lenses
  • BO, BI, BU, BD stand for base out, base in, base up, and base down. These refer to the position
    of the prism on eyeglasses that correct double vision

For contact lenses you may see additional information such as the brand, mode of wear, and BC +
DIA.

  • BC: The base curve is the measurement that indicates the curvature and shape of your contact
    lenses. This is taken when the steepness or flatness of your cornea is measured.
  • DIA: The diameter is the measurement of the length that your contacts need to be to
    completely cover your cornea.
Posted on by Dr. Elisa Xiao

Are optometrists, opticians, and ophthalmologists the same?

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As a patient, understanding the role and the services offered by each of these three eye care
professionals will help you get the specific eye care you need, know what questions to ask, and work
with your health care provider to determine appropriate solutions that work for you.

Optometrists

Optometrists perform eye exams to check the overall health of your eyes and issue prescriptions for contact lenses or glasses, or low vision devices. The optometrist will perform a number of tests including visual acuity (how well you can see letters/symbols from a distance and near), your ability to see colour, your depth perception, retinal health, the pressure inside your eyes etc. The optometrist may use eye drops to dilate your pupils to help them detect conditions such as glaucoma, cataracts and macular degeneration and more.

Ophthalmologists

An ophthalmologist is a medical doctor who specializes in eye health and related diseases. Ophthalmologists undergo post-graduate training that qualifies them to treat eye diseases both medically and surgically. Ophthalmologists provide surgical solutions to common eye problems such as cataracts, and monitor eye conditions like glaucoma as well as perform laser corrective surgery.

Opticians

Opticians fit, adjust and dispense prescription and non-prescription eyewear. They do not perform eye exams nor prescribe but can assist with filling your prescription, adjusting glasses, and ordering new/replacement contact lenses.

Posted on by Dr. Melody Tong

Are You Ready For Your Eye Exam?

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Having an annual eye exam is a great way to not only take care of your eyes but your overall health as well. Eye exams can detect early signs of conditions such as diabetes and high blood pressure. Here are some tips to help you make the most of your next visit!

What to think about:

  • Have I noticed any eye problems such as blurry vision, flashes of light, floaters, redness, or double vision?
  • Are my daily activities being affected by my vision?
  • How do I take care of my contact lenses or glasses
  • Have I had any surgeries or injuries in my eyes that I could let the doctor know about?
  • Any family history of eye conditions such as glaucoma?

What to bring:

  • Your current glasses or contact lenses even if you have multiple pairs for different tasks
  • A list of your medications/supplements you are taking
  • Have someone who can drive you home or a method of transportation ready for if you have your eyes dilated. This happens often in yearly eye exams and can make you sensitive to light and have blurry near vision (~4-6 hours)
  • Vision and health insurance information

Questions to ask:

  • Differences between contacts and glasses for you and how this compares to surgery options as well?
  • If anything has changed in my ocular health since the last visit?
  • What any symptoms you may have mean and what you can do to prevent them from getting worse or resolve?
  • When should I return for my next visit?

Posted on by Dr. Elisa Xiao

Are Cosmetic (Color) Contact Lenses Safe?

photo credit: drtavel.com

Cosmetic contact lenses or colored contact lenses may seem harmless but can lead to severe eye problems or loss of vision if not fit by an eye specialist. You need to have a prescription for contact lenses as they are deemed medical devices by the U.S. Food and Drug Administration (FDA). Non- prescription contacts can create problems due to issues such as poor fitting or unclean packing/creation.

When contact lenses not specifically fitted and sized for your eyes are worn, the cornea may be scratched, potentially leading to the following:

  • Painful corneal abrasion
  • Decreased vision
  • Redness, soreness, itching
  • Sensitivity to light
  • Allergic reactions
  • Corneal ulcers

Eye infections are also very common in non-prescribed contact lenses and may lead to the following:

  • Persistent eye pain
  • Decreased vision
  • Sensitivity to light
  • Discharge from the eye (this could be green/yellowish mucus like or more watery)

Discussing your options and proper contact lenses hygiene with an eye care professional, having the
proper measurements of your eyes taken, and getting a valid prescription is an easy way to avoid these
potentially life changing complications.

Posted on by Dr. Sherman Tung

Interested in Refractive Eye Surgery?

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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.

Posted on by Dr. Melody Tong

What is my Visual Field?

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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:

  • Glaucoma
  • Multiple sclerosis
  • Thyroid eye disease
  • Strokes
  • Finding blind spots (scotomas)
  • Diabetes
  • Hypertension

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.

Posted on by Dr. Elisa Xiao

Is it Blepharitis?

Blepharitis is when you have inflammation of your eyelids. Sometimes the cause is from skin conditions
such as dandruff or rosacea while other times the cause could be from overpopulation of bacteria or
even parasitic mites called demodex.

Image from: https://www.allaboutvision.com

Some signs or symptoms you may be experiencing include:

  • Red, swollen eyes
  • A gritty or burning sensation in your eyes
  • Excessive tearing or itching
  • Dry eyes or crusted eyelashes
  • Increased sensitivity to light
  • Dandruff-like scales on the eyelashes
  • Blocked eyelid glands
  • Eyelashes may fall out of be misdirected inwards causing damage to the cornea
  • Increased risk of infection

So what can you do?

With so many varying signs and possible causes it is important to have a comprehensive eye exam in
order to determine the type of blepharitis you may have. Once determined a specified treatment plan
can be made to manage the condition. Luckily, in many cases taking care of your eyelid hygiene,
whether in office or at home, is a simple enough method in keeping the symptoms of blepharitis at bay
and from affecting your daily life. It is important to remember that this will likely be a long term plan.
Treatments in office or at home may help jump start your recovery, but proper hygiene must be
maintained overtime, or the symptoms of blepharitis may return.

At-home ocular hygiene tips:

  • Frequently wash your the scalp and face
  • Warm compresses to help soften crust and help unclog oil glands present in eyelids
  • Use artificial tears (often helpful when placed in the fridge to bring down inflammation)
  • Limit or stop using eye makeup during treatment, as it makes lid hygiene more difficult.
  • Nutrition changes/supplements such as omega-3s

More severe cases may warrant in-office treatments:

Photo credit: Eye Health Shop, 2023

  • Intense Pulsed Light therapy, involving the application of bright red light pulses to your eyelids
  • BlephEx®, which involves cleaning your eyelid margins with microblepharoexfoliation.
  • Lipiflow or other dry eye focused treatments may be used concurrently
  • Depending on your case antibiotics or steroids or tea tree oil products may be prescribed
  • Products may be available in office to complement treatment, such as BIHOCL or eyelid scrubs
Posted on by Dr. Sherman Tung

Ever Heard of Computer Vision Syndrome?

Photo credit: healthjade.net

Almost everyone is guilty of spending an excessive amount of time on a screen and it is very common to feel symptoms of eyestrain and fatigue associated with digital use; this is known as Computer Vision Syndrome (CVS) or digital eye strain. As the name implies, excessive screen use causes stress on your eyes after reading or staring at a digital device for hours at a time. Some common symptoms of computer vision syndrome include eyestrain, headaches, dryness of the eyes, neck pain, and blurred vision over time.

Since it is unrealistic for us as optometrists to expect patients to avoid computers or excessive screen time, what are some ways to alleviate symptoms and avoid exacerbation of CVS? It is helpful to assess your desk or workstation for proper lighting and working distances. It is also important to be mindful of one’s posture throughout the day and ensure you are wearing proper visual correction such as glasses or contacts to avoid further eyestrain.

Photo credit: Ergomaker.com

Tips for avoiding eye strain

  1. Decrease the brightness of your screen
  2. Avoid letting yourself get closer to the screen throughout the day
  3. Take breaks (every 20 minutes look at something 20 feet away for 20 seconds)
  4. Wear an office or anti-fatigue lens while working
  5. Remember to blink consistently
  6. Stay hydrated

Following these simple tips will not only improve the way your eyes feel, but will naturally improve productivity, efficiency, and well-being throughout the day.

Posted on by Dr. Elisa Xiao

Why Do I Need To Get My Eyes Dilated?

It’s not the most comfortable experience, but…

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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
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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.
Posted on by Dr. Melody Tong

What is Uveitis?

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
  • Sensitivity to light
  • 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.