The earliest finding in glaucoma, particularly the common open-angle type, is often no noticeable symptoms, as it slowly steals peripheral (side) vision, making it the "silent thief of sight" until significant optic nerve damage has occurred. While a routine dilated eye exam can reveal early signs like subtle peripheral vision loss or changes in optic nerve appearance, some may notice slight difficulty adjusting to low light or cloudy vision, but by the time symptoms are obvious, it's often moderate to advanced.
Early Stage Glaucoma: When Detection Saves Your Sight
At this stage, your eye doctor can detect changes in your optic nerve through specialized testing, but you feel completely fine. Your vision is still normal, and you have no symptoms whatsoever.
Gradual loss of peripheral vision, often in both eyes: This is typically the earliest sign of glaucoma. You might notice that you can't see objects out of the corner of your eye as well as you used to. Over time, this peripheral vision loss can worsen, leading to tunnel vision.
No symptoms in early stages. Gradually, patchy blind spots in your side vision. Side vision also is called peripheral vision. In later stages, difficulty seeing things in your central vision.
Over time, you may slowly lose vision, usually starting with your side (peripheral) vision. Because it happens slowly, you may not notice your vision is changing at first. But as glaucoma progresses, you may experience blurry vision or vision loss.
The rule of 5 is a simple rule for detecting retinal nerve fiber layer (RNFL) change on spectral-domain OCT (SD-OCT), in which a loss of 5 μm of global RNFL on a follow-up test is considered evidence of significant change when compared with the baseline.
On average, let's take a closer look at the relationship between intraocular pressure and going blind from glaucoma: 21-25 mmHg – if left untreated, it takes about 15 years for glaucoma to cause blindness. 25-30 mmHg – if left untreated, it takes about seven years for glaucoma to cause blindness.
But most forms of glaucoma are treatable, especially when diagnosed early. And with care and careful management, it's possible to delay — or even prevent — permanent vision loss.
Occasionally, a person may have a “borderline” eye pressure, which means that, although the pressure is elevated, there is no evidence of glaucoma damage.
Halos around lights: Rainbow-like rings around lights, especially at night, can be a red flag. Eye pain or pressure: A dull ache or intense pressure may signal acute glaucoma.
Causes of Glaucoma
When the pressure inside a person's eye is too high for a particular optic nerve, whatever that pressure measurement may be, glaucoma will develop. Glaucoma is the second-leading cause of blindness in the U.S. It most often occurs in people over age 40, although an infant (congenital) form of glaucoma exists.
No, digital eye strain does not cause glaucoma. While prolonged screen time creates uncomfortable symptoms like tired, dry eyes, headaches, and blurred vision, these symptoms result from muscle fatigue and reduced blinking rather than damage to the optic nerve.
Stage One: Suspect or Early Glaucoma
At this stage, your eye pressure may be elevated, or our doctors may notice early changes to your optic nerve, but you have no vision loss yet. You will feel completely normal, and your eyes will look and feel healthy.
While there is no cure for glaucoma, treatment can significantly slow or prevent further vision loss. Treatment options include: Medications: Prescription eye drops and oral medications can help reduce IOP by decreasing fluid production or improving drainage.
Exercises that Can Raise Eye Pressure
Exercise that involves straining or bearing down, such as weight-lifting or inverted sit-ups, has the opposite effect. Many yoga poses, those that incorporate inversion, can also have a negative effect on eye pressure.
Certain inflammatory eye diseases (like optic neuritis), retinal diseases, or past injuries can also affect the optic nerve's appearance or visual field test results, making them appear similar to glaucoma.
With the eye's drainage channel completely blocked, eye pressure skyrockets in a very short amount of time. This spike often leads to intense, sudden pain in the eye that can even cause vomiting. The pain can further spread to the head, causing intermittent headaches.
The damage caused by glaucoma can't be reversed. But treatment and regular checkups can help slow or prevent vision loss, especially if the disease is found in its early stages. Treatment of glaucoma aims to lower intraocular pressure.
Biological Response to Stress: When a person experiences stress or anxiety, their body initiates a biological response. Stress hormones like cortisol are released, blood pressure rises, and heart rate increases. Studies show that stress responses can also raise eye pressure, a key risk factor for glaucoma.