Preview Case
topic : The treatment of Headaces cause of low ametropia and pre-presbyopia
By Dr.Loft,O.D
Case History
Yatita, a 42-year-old female patient, came in for a routine eye check-up. She has clear distance vision without glasses but experiences strain and tension in her eyes when reading, making near work increasingly difficult.
She has never worn glasses before.
She experiences daily headaches, which become more intense in the afternoon or after prolonged computer use. However, due to her work, she cannot avoid using a computer, spending 4–6 hours in front of a screen daily.
She is in good health, undergoes annual medical check-ups, and does not take any regular medications.
Preliminary Eye Exam
Visual Acuity (Unaided)
OD: 20/20
OS: 20/20
Refraction
Retinoscopy
OD: +0.50 -0.50 x 180, VA 20/20
OS: +0.25 , VA 20/20
Monocular Subjective Refraction
OD: +0.50 -0.12 x 180, VA 20/20
OS: -0.25 , VA 20/20
Best Vision Acuity (BVA) on Trial Frame
OD: +0.50 -0.12 x 180, VA 20/20
OS: +0.12 , VA 20/20
Best Corrected Visual Acuity (BCVA) on Trial Frame
OD: +0.50 -0.12 x 180, VA 20/20
OS: +0.12 , VA 20/20
Binocular Function at 6m Distance:
Horizontal Phoria: Ortho
Vertical Phoria: Ortho
Functional Testing at 40cm (Near Vision)
BCC: +1.00
NRA: +2.25 (relative to BVA)
PRA: -1.00 (relative to BVA)
Assessment
1. Simple Hyperopia (OD & OS)
2. Pre-Presbyopia
3. Normal Binocular Function
Plan
1. Full Prescription:
OD: +0.50 -0.12 x 180
OS: +0.12
2. Plus Add Single Vision Lens:
RX_Add +1.1 (Rodenstock Cosmolit B.I.G. Norm 1.6 P+1.1)
3. N/A
Discussion
At first glance, the refractive error seems minimal, but this seemingly small issue causes daily headaches for the patient. Given that her distance vision is already clear, there’s a high chance that she might opt for glasses with no prescription and blue-light filtering, or worse, continue relying on painkillers for relief.
The next question is:
Why does such a minor refractive error cause daily headaches?
The exam results indicate that the headaches are not due to binocular vision dysfunction, as her phoria results are Ortho. This leaves fatigue of the accommodative system (accommodative insufficiency) as the likely cause. This condition marks the early stages of pre-presbyopia, where the eye struggles to maintain focus for extended near tasks—such as prolonged computer use. Over time, the resulting stress on the accommodative system leads to headaches.
A Common Dilemma: Should We Correct a Minor Refractive Error?
If the patient can already see clearly at a distance, and one eye has slight hyperopia (+0.50D) while the other has nearly zero error (0.00D), should we prescribe 0.00D for both eyes instead?
Many optometrists follow the principle:
"If it ain’t broke, don’t fix it!"
This mindset is ingrained in many professionals, discouraging them from prescribing full correction even when needed.
However, human vision is “binocular” our eyes function as a system, much like the front wheels of a car turning together. If one part of the system is off-balance, the entire function is compromised, leading to discomfort and strain. Just as car wheels require proper alignment for smooth driving, our eyes need balanced vision for optimal comfort.
To achieve this balance, we must ensure that both eyes focus together (correcting any astigmatism) and that their focal points are equidistant from the retina. This equalizes the accommodative response, preventing "fluctuations in accommodation” a condition where the eyes struggle to find a stable focus, causing ongoing strain and headaches.
Many practitioners mistakenly believe that “binocular balancing” means prescribing the same lens power for both eyes. This is incorrect. The goal is to “equalize accommodative effort”, not necessarily to make both prescriptions identical. The concept of Aniseikonia (differences in image size between eyes) is often cited as a reason to avoid full correction, but in practice, the effects are usually minor compared to the benefits of full correction.
Clinical Result
Upon wearing the new glasses, the patient initially felt slightly unusual due to the progressive structure of the Plus-Addition +1.1D lenses. However, she immediately noticed that her distance vision felt more relaxed. Although she could see clearly without glasses, wearing them provided added clarity and reduced strain.
For near work, she no longer needed to strain her eyes. The only adoption issue was peripheral aberration , which is expected when adapting to progressive lenses for the first time. However, after discussing with her for 30 minutes, her discomfort significantly reduced. Based on this, I estimate that she will fully adapt to the lenses within two days.
This case highlights the importance of full correction—even for small refractive errors—when considering the overall function of the binocular visual system.
Product Used
Lens:Rodenstock Cosmolit B.I.G. Norm Plus +1.1
Frame Lindberg Spirit 2528 (Color: P10/P10)
For more information on Plus Add Single Vision Lenses, visit:
https://www.loftoptometry.com/whatnew/view/64
Loft Optometry
578 Wacharapol Rd, Tharang, Bangkhen, BKK 10220
