On Thursday, 20th, I had an eye exam to obtain a badly needed updated prescription. My eyes have definitely changed over the past couple of years which led me to wonder how my last three eye exams compared to each other and if there were any interesting trends. After examining my last three exams (all from different eye care clinics), I realized I didn’t have any idea what they meant so I decided to have AI decipher them for me. ChatGPT gave me the following breakdown of my prescriptions and I discovered my 2023 prescription might have had errors.
Me: Attached are three eye exams that I have had over the past few years. Can you give me a summary of my vision and direction things are going."Here’s a summary of your vision changes over the years based on your prescriptions:Me: It seems like my 2023 result don't make a lot of sense.
2017 Prescription (Eye Clinic A)
Right Eye (OD): +1.25 (Sphere), -1.00 (Cylinder), 095 (Axis)
Left Eye (OS): +0.50 (Sphere)
2023 Prescription (Eye Clinic B)
Right Eye (OD): +0.75 (Sphere), +1.25 (Cylinder), Axis 3
Left Eye (OS): +1.00 (Sphere), +0.25 (Cylinder), Axis 155
Addition (for reading): +2.00
2025 Prescription (Eye Clinic C)
Right Eye (OD): +2.25 (Sphere), -1.25 (Cylinder), Axis 095
Left Eye (OS): +1.50 (Sphere), -0.25 (Cylinder), Axis 060
Addition (for reading): +2.25
Observations on Vision Changes:
Your right eye (OD) has had some fluctuation, with cylinder power shifting from -1.00 in 2017 to +1.25 in 2023, then back to -1.25 in 2025.
Your left eye (OS) has remained more stable, with slight changes in both sphere and cylinder values.
Overall trend: Your farsightedness (hyperopia) has increased (higher positive sphere values). Your astigmatism has also fluctuated, particularly in your right eye.
Reading addition power has increased slightly, from +2.00 in 2023 to +2.25 in 2025, indicating that presbyopia (age-related near-vision difficulty) is progressing.
Direction Things Are Going:
Your distance vision is changing, particularly with increasing hyperopia.
Your near vision needs stronger correction, which is expected with age.
Your astigmatism corrections are varying, suggesting possible prescription adjustments for better clarity.
It would be beneficial to check in with your eye doctor more frequently to monitor these changes and ensure you’re getting the best correction for both distance and near vision."
"You're right to question the 2023 results—there's a significant jump compared to the other years. Let’s break it down:Back to Homepage
Farsightedness (Sphere)
Your right eye (RT) in 2023 was +0.75, while in 2017 it was +1.25, and in 2025 it jumped to +2.25. That’s a large fluctuation.
Your left eye (LT) went from +0.50 (2017) to +1.00 (2023) and then +1.50 (2025)—a more steady increase.
Astigmatism (Cylinder)
The biggest inconsistency is in your right eye's astigmatism.
2017: -1.00
2023: +1.25 (this sign flip is unusual!)
2025: -1.25 (back to negative)
Your left eye’s astigmatism values are much more stable, though they still fluctuate.
Near Vision Addition
This has steadily increased over time, which is expected with age-related presbyopia.
Possible Explanations
The 2023 exam may have been an outlier, possibly due to measurement differences, temporary vision fluctuations, or even a misreading.
The cylinder sign flip in 2023 suggests either a different measurement method or an incorrect entry.
What This Means
Your 2025 prescription aligns more closely with your earlier trend (2017). The 2023 values seem inconsistent, especially with the right eye’s astigmatism. If your glasses based on the 2023 prescription didn’t work well, this might explain why!"