Have you been told you have 20/20 vision but still struggle with glare, halos, or ghosting? You’re not imagining it.
Standard eye charts objectively measure vision but it’s hard to gauge the quality of what you actually see. Higher Order Aberrations (HOAs) affect quality of vision: contrast, clarity, and night vision. Two people with 20/20 can see the world completely differently if one is affected by HOA’s.
What Are HOAs?
Think of your eye as a camera:
- Lower order aberrations (nearsightedness, farsightedness, astigmatism) = out of focus. Fixable with glasses or soft contacts.
- Higher order aberrations = light scatters instead of focusing to a single perfect point, creating visual “noise.”
HOAs cause visual distortions such as glare, halos, and poor contrast sensitivity that standard correction cannot fix.
Common Types of HOAs
| Type | What It Looks Like | Most Common In |
| Coma | Comet-like blur trailing from lights | Keratoconus, post-surgery |
| Spherical Aberration | Rounded halo around lights | Post-LASIK, aging eyes |
| Trefoil | Triangular glare | Irregular astigmatism, post-radial keratotomy or (RK) |
Who Has Significant HOAs?
Certain conditions cause severe, disruptive HOAs:
- Keratoconus and other corneal ectasias
- Post-LASIK, RK, or PRK complications
- Corneal scarring, transplants, or trauma
- Irregular astigmatism
- Large pupils (worse at night)
- Post-surgical complications
HOA technology is particularly helpful for patients with ocular surface conditions like keratoconus or dry eye.
How HOAs Are Measured: Wavefront Aberrometry
Diagnosing HOAs requires advanced technology like the Ovitz wavefront aberrometer, which we have at our office. These devices create a detailed map of the patient’s eye and identify areas of aberration that need to be corrected.
The key measurement is RMS (Root Mean Square) :
| RMS Value | Category | Likely Benefit from HOA Correction |
| Under 0.3μm | Low | Only performance-driven patients |
| 0.3–0.5μm | Moderate | Likely beneficial |
| Over 0.6μm | High | Very likely beneficial |
The lab then creates the inverse of your wavefront error and adds it to your scleral lens—neutralizing aberrations instead of just masking them.
The Solution: Wavefront-Guided Scleral Lenses – How They Work:
- Achieve a stable fit (scleral lenses are ideal—large, no rotation)
- Measure residual HOAs over the stabilized lens
- Customize optics (like LASIK on the contact lens)
- Verify and refine
The Results
According to the Scleral Lens Education Society (sclerallens.org), data showed that typically you get an average of 60% reduction in higher order aberrations, and essentially every patient reported subjective visual improvement.
Real Patient Example
A 24-year-old with keratoconus had 20/20 vision but reported “shadowing of letters.” His HOA RMS measured 1.42μm. After wavefront-guided scleral lenses, his RMS dropped to 0.39μm. He described his vision as “smooth” and “more 3D and bold.”
Who Is the Ideal Candidate?
Not everyone needs HOA correction. The ideal candidate:
- Is already a candidate for scleral lenses
- Has one or two dominant HOAs (not many mildly elevated ones)
- Still experiences ghosting, glare, halos, or poor night vision despite good acuity
Limitations
- Not everyone needs it. Many do great with standard sclerals. HOA correction is the “next step” for residual complaints.
- Stability is non-negotiable, If the lens rotates, vision worsens.
- Not every clinic offers it – relatively new technology
- Cost and time. Highly customized lenses require multiple visits; adding HOA correction to lenses increases the fitting time by about a month.
The Bottom Line
HOAs explain why 20/20 vision can still feel “off”, especially at night. Wavefront-guided scleral lenses, measured with advanced aberrometers like Ovitz, can reduce HOAs by 50–80%, transforming “good enough” vision into truly high-definition sight.
If you experience glare, halos, ghosting, or starbursts, particularly at night, and standard scleral lenses haven’t fully resolved them, ask us about wavefront-guided HOA scleral lenses!
