Toric spectacle lenses were first described in 1847 by George Biddell Airy, and their adoption was, presumably, gradual at that time. Today, correction of astigmatism with glasses is routine. In a recent survey, 87.2% of spectacle prescriptions contained at least 0.25 dioptres (D) of cylinder [1].
Astigmatism is common: approximately 40% of the population has more than 1D of corneal astigmatism [2]. The first toric intraocular lenses (IOLs) were implanted in 1991 by Kimiya Shimizu, and toric IOLs have consistently been shown to reduce astigmatism and improve unaided acuity in patients with astigmatism [3,4]. Despite this, uptake remains surprisingly low. Survey data from ESCRS suggest that only around 18% of patients with clinically significant astigmatism receive a toric IOL [5].
The slow adoption of toric IOLs can be understood by examining barriers across structure, process and outcomes. Structurally, many surgical settings lack access to appropriate technology or reimbursement models that support toric IOL use, creating financial and logistical hurdles. At the process level, toric implantation requires additional measurements, careful patient selection and precise alignment, increasing workflow complexity and reliance on surgeon confidence and training. From an outcomes perspective, although toric IOLs clearly reduce postoperative astigmatism and improve unaided vision, the perceived benefit over standard IOLs, particularly for lower levels of astigmatism, is not always communicated or valued by patients, providers or payers.
Together, these factors help explain the cautious and uneven implementation of toric IOLs despite strong clinical evidence. In this article, I will explore these challenges and potential solutions.
Structural barriers: cost and technology
Planning for toric IOLs requires understanding both the quantity (magnitude and axis) and quality (regular vs irregular) of astigmatism. All cataract surgery units will have a biometer capable of measuring the quantity of astigmatism, but not all have access to corneal topography or tomography. The cost of acquiring such devices can be a barrier to adoption of toric lenses.
Fortunately, modern biometers increasingly incorporate basic corneal tomography modules that are sufficient to identify eyes requiring more detailed assessment. These modules are less expensive than dedicated tomographers and can provide a pragmatic entry point into toric IOL use.
Toric IOLs typically cost three to four times the price of non-toric equivalents. In addition to the lens cost, toric implantation requires extra planning time, counselling and intraoperative steps, all of which represent real costs. Some additional theatre instrumentation is also required to facilitate accurate alignment. Augmented reality or digital marking systems can refine accuracy but should not be considered essential. Good results can be achieved using manual marking with a degree gauge and axis marker, although even these involve modest additional expense.
In many healthcare systems there is no mechanism to recoup these additional costs. State-funded cataract services often provide limited or inconsistent coverage for toric IOLs, and private insurers frequently exclude them. In private practice, the cost of the lens and associated testing usually falls to the patient, while public systems typically do not permit patient ‘top-up’ payments. Broader discussions around pricing, reimbursement and whether surgeons should merely cover costs or generate profit from premium services are important but beyond the scope of this article.
Process barriers
Measurement and calculation
At minimum, toric IOL calculation requires keratometry from a biometer and some qualitative assessment of corneal astigmatism. Some biometers can perform both functions but many surgeons use separate devices. Calculations can be performed either on the biometer or using online calculators. Online calculators allow entry of K readings from multiple devices to help ‘smooth’ measurement error, but they require manual data entry, which is time-consuming and introduces the risk of transcription errors. This process requires focused, interruption-free time.
In my own practice, I use keratometry from the IOLMaster and Pentacam AXL and enter these data into the Barrett toric calculator [6]. Integrated systems such as the Zeiss Veracity platform (available in USA) reduce manual data handling, and similar systems are anticipated in Europe.
If a disagreement is found between devices, in the axis or magnitude of astigmatism, options include averaging readings, repeating measurements or deciding against a toric IOL. The choice depends on the magnitude of astigmatism, the size of the disagreement, patient expectations, willingness to return for repeat testing and practical considerations, such as the distance the patient lives from clinic.
How low do you go?
A fundamental, initial question in toric lens adoption is deciding the threshold of corneal astigmatism above which to offer toric lenses. Most new toric users start out using these lenses in higher levels of astigmatism (>2D) and, when comfortable with the process, consider lowering the threshold. I routinely offer toric IOLs to patients with consistent measurements of more than 1.25D of corneal astigmatism on two devices, unless the eye is amblyopic.
A critical and often under-appreciated factor in these decisions is that of surgically-induced astigmatism (SIA). While frequently simplified to a small, constant value, SIA is poorly understood, rarely measured by individual surgeons, and can be unpredictable. Although the cornea is usually flattened along the meridian of the main incision, it may also, occasionally, steepen depending on multiple (and often indeterminate) variables [7]. As a result, patients with relatively modest preoperative astigmatism can, occasionally, be left with higher and visually-significant postoperative astigmatism, even when operating on the steep meridian. These rare cases highlight the limitations of relying on averaged SIA values and reinforce the need for caution when deciding how low a level of astigmatism to correct.
For this reason, I selectively offer toric IOLs to patients with consistent measurements of corneal astigmatism above 0.75D who are likely to have a low tolerance for residual astigmatism.
Below 0.75D, the repeatability of astigmatism measurements, particularly axis, drops off significantly [8]. With current technology, routine toric implantation at lower levels than 0.75D would lead to an unacceptably high rate of recalls for repeat biometry.
Patient selection: irregular astigmatism
For surgeons early in their toric experience, the simplest approach is to avoid toric IOLs in eyes with irregular astigmatism. This raises the question: how irregular is irregular?
Figure 1: Irregular(ish) astigmatism.
Many corneas have a combination of regular and irregular components. In Figure 1, a patient with a dense cataract had long-standing paracentral corneal scarring from previous keratitis (Figure 1A). On IOLMaster (Figure 1B) and Pentacam (Figure 1D) the axes of astigmatism were similar but the magnitudes of astigmatism were quite different. Anterior shape was regular in the central 3mm but irregular outside that (Figure 1C). The patient was realistic about the (uncertain) outcome, was never going to use a rigid contact lens and was keen to attempt to optimise unaided acuity with a toric lens. We aimed to correct the lower amount (2.07D) of astigmatism as measured by the IOLMaster. Surprisingly, the patient achieved acuity of 6/7.5 unaided after surgery. Despite this isolated good result, caution should be exercised when considering toric lenses in partly irregular corneas.
Toric IOLs can often correct the regular component and ‘debulk’ the astigmatism. Factors to consider include historical best-corrected visual acuity (good BCVA suggests predominantly regular astigmatism), the shape of the central 3mm zone, patient expectations and the likelihood of future rigid contact lens use for residual irregular astigmatism. Prescribing rigid gas permeable or scleral lenses after toric lens implantation is difficult and toric IOLs should not be used when postoperative use of a rigid contact lens is anticipated. A cautious approach is advised in patients with irregular astigmatism.
Outcomes and communication: framing the discussion
In communicating with cataract patients and planning surgery, many experienced surgeons are careful to under-promise and overdeliver. There is a concern that introducing ‘premium’ lens technology (especially if the patient must pay for it) ratchets up the expectation and makes it difficult to under-promise on the outcome.
In any candid discussion about visual outcomes after cataract surgery, surgeons must be guided by robust outcome data. Surgeons can be affected by optimism bias (a tendency to overestimate positive outcomes) [9]. Without familiarity with personal and real-world results, it is easy to unintentionally overestimate what surgery can deliver.
Visual and refractive outcomes are constrained by factors such as effective lens position variability and IOL manufacturing tolerances, neither of which are under surgical control. Residual astigmatism, however, is modifiable. If corneal astigmatism is left uncorrected and refractive outcomes are not critically analysed, the likelihood of achieving excellent unaided vision can easily be overestimated.
Real-world data reinforce this point. Analyses from the UK National Ophthalmology Database show that only 75.3% of eyes achieve unaided visual acuity of 6/12 after cataract surgery. Even after excluding eyes with ocular co-pathology, this rises to just 80.9% [10].
Our own analysis of more than 9000 eyes further highlights the impact of uncorrected astigmatism. When toric IOLs were not used, unaided visual acuity meeting the UK driving standard (6/12) was achieved by only 81% of eyes with 1–1.5D of astigmatism and 71% of those with 1.5–2.0D [11].
Using these data helps to communicate the benefit of toric IOLs whilst making it clear that no guarantee regarding the outcome can be offered. Framing outcomes around functional vision, rather than ‘perfect vision’ or 6/6 acuity, may be more effective. For cataract populations, driving standard vision is a meaningful and easily understood benchmark. Randomised controlled trials show that over 92–97% of patients with toric IOLs achieve unaided distance visual acuity that meets the driving standard (6/12) if the eye is otherwise healthy [3,4].
Conclusion
In conclusion, the underutilisation of toric IOLs is not a reflection of weak clinical evidence but rather the cumulative effect of structural, procedural and perceptual barriers. Financial constraints, technology access, workflow complexity and uncertainty around measurement all contribute to surgeon caution, particularly at lower levels of astigmatism. Yet outcome data consistently demonstrate that meaningful improvements in functional unaided vision are achievable. By refining measurement strategies, adopting pragmatic thresholds for treatment and communicating benefits in terms that matter to patients, surgeons can integrate toric IOLs more confidently and consistently into routine cataract practice. Wider adoption will depend not only on widening access to technology, but also on cultural and systemic shifts that recognise astigmatism correction as a functional necessity rather than a premium luxury.
References
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2. Knox Cartwright NE, Johnston RL, Jaycock PD, et al. The Cataract National Dataset electronic multicentre audit of 55,567 operations: when should IOLMaster biometric measurements be rechecked? Eye (Lond) 2010;24(5):894–900.
3. Holland E, Lane S, Horn JD, et al. The AcrySof Toric intraocular lens in subjects with cataracts and corneal astigmatism: a randomized, subject-masked, parallel-group, 1-year study. Ophthalmology 2010;117(11):2104–11.
4. Waltz KL, Featherstone K, Tsai L, Trentacost D. Clinical outcomes of TECNIS toric intraocular lens implantation after cataract removal in patients with corneal astigmatism. Ophthalmology 2015;122(1):39–47.
5. www.escrs.org/media/
2lhhm3yl/final_escrs_
clinicaltrendssurvey2023_sept24.pdf
6. https://calc.apacrs.org/toric_calculator20/
Toric%20Calculator.aspx
7. Alfaqawi F, Pagano L, Arbabi EM, et al. Cataract surgery has minimal effect on corneal shape. BMJ Open Ophthalmol 2025;10(1):e001920.
8. Personal data; manuscript in preparation.
9. Torrens C, Miquel J, Santana F. Optimistic bias: the more you do, the better you think it goes. Survey analysis of reverse shoulder arthroplasty. Patient Relat Outcome Meas 2019;10:277–82.
10. Day AC, Donachie PHJ, Sparrow JM, et al. The Royal College of Ophthalmologists’ National Ophthalmology Database study of cataract surgery: report 1, visual outcomes and complications. Eye 2015;29(4):552–60.
11. Nghiem AZ, Lin P-F, Maurino V, Flynn TH. Effect of preoperative keratometric astigmatism on uncorrected distance visual acuity after cataract surgery. J Cataract Refract Surg 2022;48(2):245–6.
[All links last accessed April 2026]
Declaration of competing interests: None declared.
