How to Read Eye Reports and Understand Eye Test Results

confusing for patients. However these reports provide important information about vision eye pressure retinal health and possible early signs of eye disease.
Understanding the key parts of an eye report helps patients know whether results are normal when further testing may be needed and what questions to ask their doctor. Many eye diseases such as glaucoma diabetic retinopathy and macular degeneration develop slowly and may not cause symptoms in the early stages. Eye reports help detect these conditions before vision loss occurs.
This guide explains common eye reports in simple language including prescription reports eye pressure readings visual field reports and retinal imaging results.

Types of Eye Test Reports
​Different eye examinations produce different types of reports. Each report focuses on a specific part of eye health.

Report Type	Tests Included	What It Evaluates
Refraction report	Glasses prescription test	Vision clarity and focusing ability
Eye pressure report	Tonometry	Risk of glaucoma
Imaging reports	OCT retinal scans fundus photographs	Retina and optic nerve health
Visual field report	Humphrey visual field test	Peripheral vision loss

Doctors combine information from several reports to evaluate overall eye health.

Understanding a Refraction Report
A refraction report shows the prescription used for glasses or contact lenses. The report includes measurements for each eye.
Example format
OD -2.50 -0.75 x 90
OS -1.75 -1.00 x 85

Meaning of Each Parameter

Parameter	Meaning
OD	Right eye
OS	Left eye
Sphere value	Nearsighted or farsighted power
Cylinder value	Amount of astigmatism
Axis	Direction of astigmatism

Negative numbers indicate nearsightedness while positive numbers indicate farsightedness. Cylinder and axis values describe the degree and orientation of astigmatism.
Sudden large changes in prescription may require further evaluation because they can sometimes indicate cataract, glaucoma development or other eye disease conditions.

Understanding Eye Pressure Reports
Tonometry measures the pressure inside the eye called intraocular pressure.
Example report
IOP OD 24 mmHg
IOP OS 22 mmHg

Eye Pressure Range	Interpretation
10 to 21 mmHg	Typical pressure range
22 to 26 mmHg	Higher than normal pressure
Above 26 mmHg	Possible glaucoma risk

Eye pressure is only one factor in diagnosing glaucoma. Doctors consider a triad of eye pressure, optic nerve appearance and visual field results in the diagnosis of glaucoma. 

Understanding Visual Field Reports
Visual field tests measure peripheral and central vision and help detect early glaucoma damage.
Key values in a Humphrey visual field report include

Indicator	Typical Range	Meaning
MD Mean Deviation	Around -2 to +2 dB	Overall sensitivity of vision
PSD Pattern Standard Deviation	Less than 2 dB	Localized defects
VFI Visual Field Index	90 to 100 percent	Overall visual field health
Fixation Loss	Less than 15 percent	Test reliability

Doctors also look for patterns in the visual field map that may suggest a diagnosis of glaucoma or progression.

Understanding OCT Scan Reports
Optical coherence tomography OCT scans provide cross sectional images of the retina and optic nerve.
These scans measure the thickness of different retinal layers.

Layer	Typical Thickness	Possible Concern
RNFL Retinal nerve fiber layer	90 to 120 microns	Thinning may indicate loss of nerve fibre and possibly glaucoma.
Macular thickness	220 to 280 microns	Increased thickness may indicate swelling
Ganglion cell layer	50 to 70 microns	Thinning may indicate nerve cell damage

OCT reports may include color coded maps that help doctors identify abnormal areas which aid in diagnosis.

Understanding Fundus Photograph Reports
Fundus photographs capture detailed images of the retina optic nerve and blood vessels.
These images help detect several retinal conditions.
Common findings include

• Drusen deposits which may indicate early macular degeneration
• Microaneurysms which may appear in diabetic retinopathy
• Pale optic disc which may suggest optic nerve damage

Doctors compare these images with previous scans to monitor disease progression.

Interpreting Eye Report Findings
Eye reports may contain findings that fall into different categories depending on severity.

Findings That Usually Require Routine Monitoring

Finding	Meaning	Next Step
6 by 6 vision	Normal vision	Routine eye exam
Eye pressure within typical range	Healthy pressure	Continue monitoring

Findings That May Require Additional Tests

Finding	Possible Meaning
Borderline eye pressure	Possible early glaucoma risk
Mild visual field changes	Early nerve damage
Early drusen deposits	Possible early macular degeneration

​Findings That Need Immediate Evaluation

Finding	Possible Condition
Rapid visual field loss	Progressive glaucoma
Macular fluid on OCT	Wet macular degeneration
Significant nerve fiber thinning	Optic nerve damage

Doctors evaluate these findings together with symptoms, medical history and clinical findings. Where indicated follow up tests maybe required.

Questions Patients Can Ask Their Doctor
Patients may benefit from discussing their report results with their eye doctor.
Helpful questions include

• Are these results different from my previous test
• Which findings are most important for my eye health
• Do these results suggest early eye disease
• Should the test be repeated to confirm results

Understanding the answers can help patients participate actively in their eye care decisions.

Frequently Asked Questions

Is 6 by 9 vision normal
6 by 9 vision indicates slightly reduced visual clarity but many people can still function well with this level of vision.

Is eye pressure of 24 dangerous
Eye pressure above the typical range may increase glaucoma risk and should be monitored by an eye specialist.

What does fixation loss mean in a visual field test
High fixation loss suggests the test may not be fully reliable and may need to be repeated.

Is RNFL thickness of 75 normal
Lower RNFL thickness may indicate possible optic nerve damage and should be evaluated by an eye specialist.

What does increased macular thickness indicate
Increased macular thickness may indicate retinal swelling known as macular edema.

Is astigmatism of -1.50 severe
This level of astigmatism is considered moderate and is usually corrected with glasses or contact lenses.

What does PSD value in a visual field test mean
Pattern standard deviation indicates localized visual field defects which may occur in glaucoma.

Are drusen deposits treatable
Drusen deposits may indicate early macular degeneration and may require monitoring and lifestyle changes.