Signs You Need an Eye Exam and Red Flags to Watch Out For


Just like your car needs an oil change every now and then, your eyes also require regular maintenance to keep your vision sharp. There are telltale signs which may indicate you need to see an eye care specialist to get a prescription for your glasses or contact lenses.

In the overwhelming majority of cases, that new prescription is all you need and your eyes will be as good as new. In fact, we recommend routine eye exams at least every year for children and two years for adults as our eyes are constantly changing. The recommended interval between eye exams may be shorter if you have other health or ocular conditions that require sooner follow-up or if your eyes tell you otherwise via one of the signs discussed in this post. However, there are also important warning signs you need to be aware of to prevent vision-threatening or even life-threatening complications. Who knew these two small spheres in our heads could tell us so much and even save our lives?

Disclaimer: The following list is by no means comprehensive and you should always seek medical attention if you are worried about the health of your eyes or body in general. Suggestions to seek medical attention refer to seeing an eye care specialist (preferably an ophthalmologist) or visiting your nearest emergency department.

1. Blurry Vision

If you are having progressive difficulty seeing things you once saw clearly, such as words in a book or recipe, cars in front of you when driving, people or characters on the television, you may require a new  prescription. Other signs that indicate a refractive problem include improved clarity when you squint or change positions (e.g., moving closer or further away) and getting tired more quickly than normal after reading or watching a show. Squinting helps improve clarity by limiting the amount of light that enters the eye and allows it to focus on what you really want to see. Changing positions helps by optimizing the spot at which light hits the back of the eye (the retina); if light hits the right spot, that is not just in front of or behind the retina, your eye can interpret an image that is more clear. However, if the blurry vision comes on suddenly, especially if in one eye only, there may be a more urgent problem in your eyes or elsewhere in your body and should prompt you to seek urgent medical attention.

2. Headaches

If this occurs commonly when reading along with a pattern of worsening blurry vision, it likely means that you need to schedule an eye exam to get a new prescription. However, characteristics of headaches include sudden-onset, the worst headache you’ve ever had, different from other headaches you’ve had before, confusion, profuse vomiting, double vision, difficulty speaking or slurred speech, fever, extreme neck stiffness, and significant weight loss. These characteristics can be a sign of a bleed in your brain, a stroke, a brain infection, or cancer and should prompt you to seek urgent medical attention.

3. Floaters, Flashes, & Shadows

Floaters are a common symptom, especially with age as the jelly in the back of the eye becomes more liquid. However, if you experience new flashes and floaters, especially if you notice many in one eye all at once and alongside a ‘shadow’ or ‘curtain’ that is blocking a part of your vision, is please seek urgent medical attention as these can be signs of a serious, vision-threating ocular emergency such as retinal detachment, retinal break/tear, or macular hole.

4. Red Eyes

This sign causes a lot of worry for many and understandably so. Thankfully, red eyes are often just a sign of fatigue or allergies. In some cases, you might see a small area of blood in the white part of the eye called the conjunctiva and, interestingly, this is usually also nothing to worry about and could have happened because of something as simple as a cough or sneeze. On the other hand, some red eye warning features that should prompt you to seek urgent medical attention include pain, headache, new blurry vision, vomiting, eyelid swelling, fever, an eye that looks like it is “popping out”, discharge (especially if thick/yellow or watery in both eyes – try not to touch your eyes to reduce spread!), the possibility of something getting into the eye (especially metal), light sensitivity, and recent eye surgery.

5. Eye Turn

What is commonly referred to as “lazy eye” (ambylopia) can occur for many reasons including one eye to work harder than the other because of a difference in the prescription between the eyes (anisometropia), the brain not effectively signalling the eye muscles to move, and trauma causing an eye muscle to be trapped. This may occur alongside double vision (diplopia) which, if only present when both eyes are open, can be caused by a neurological/brain-related issue that can be serious. All cases of ambylopia require a timely comprehensive eye exam to determine if and how the eye turn (strabismus) can be treated (often with great success in younger children).

6. ‘White’ Pupils

How many times have you had your picture taken only to later see that your eyes were red? Fortunately, photo-editing software has red eye correction so you can post your best shots without looking evil in the photo. This occurs because you were in the optimal position for light to shine through your eye and hit your retina at the perfect angle. When eye care specialists examine your eyes, they exploit this effect to assess for a ‘red reflex’ which is normal and usually signifies a healthy eye. In rare cases, you may notice someone’s eyes to be ‘white’ rather than red, termed leukocoria in medicine. This may occur because of something in the eye that blocks the path light takes to reach the retina so that the brain can interpret the image it is seeing. Leukocoria is never normal and is a sign of something wrong with the eye. Causes include issues with the cornea, cataract, cancer (retinoblastoma), and retinal detachment and leukocoria should prompt you to seek urgent medical attention.

Written By: Prem Nichani, PGY1 Ophthalmology, Department of Ophthalmology & Vision Sciences, Temerty Faculty of Medicine, University of Toronto

Leave a Reply

Your email address will not be published.

This field is required.

You may use these <abbr title="HyperText Markup Language">html</abbr> tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

*This field is required.