Related Experiment Video
Updated: Jun 26, 2026
05:46
Correction of Presbyopia by Monocular Bi-Aspheric Ablation Profile
Published on: September 20, 2024
Prescribing soft contact lenses for astigmatism
Philip B Morgan1, Nathan Efron
1Eurolens Research, The University of Manchester, Manchester, United Kingdom.
Summary
Improvements in toric soft lens design have led to increased fitting rates. Current prescribing patterns suggest near-universal adoption for astigmatism of 1.00D or more, with monthly replacements favored.
Area of Science:
- Ophthalmology
- Optometry
- Contact Lens Technology
Background:
- Significant advancements in toric soft contact lens design have occurred over the last 30 years.
- Toric lenses correct astigmatism, a common refractive error.
- Contact lens fitting surveys provide valuable data on prescribing trends.
Purpose of the Study:
- To analyze the trend of toric soft lens fitting in proportion to all soft lens fittings.
- To assess the current prevalence of toric lens prescribing.
- To compare current prescribing rates with potential adoption based on astigmatism severity.
Main Methods:
- Analysis of data from annual contact lens fitting surveys.
- Calculation of toric lens fitting as a percentage of all soft lenses.
- Exclusion of cosmetic tints, monovision, and multifocal lenses for accurate rate calculation.
- Comparison of current rates with theoretical rates for astigmatism correction.
Main Results:
- A consistent increase in the proportion of toric soft lenses fitted over three decades.
- The current toric lens prescribing rate is approximately 34% (excluding specific lens types).
- This rate approximates the theoretical maximum if all astigmatism cases (≥1.00D) were fitted with toric lenses.
- Toric lenses are more frequently fitted to males and for monthly replacement schedules compared to daily replacements.
Conclusions:
- Toric soft lens technology has advanced, driving increased adoption.
- Current prescribing practices align with the potential need for astigmatism correction.
- Demographic and replacement frequency patterns exist for toric lens wearers.
Related Concept Videos
01:16Focusing of Light in the Eye
Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...
01:27Open Angle Glaucoma: Treatment
In open-angle glaucoma, the iridocorneal angle remains open, but the trabecular meshwork becomes stiff, slowing down the outflow of aqueous humor. This causes a buildup of aqueous humor in the anterior chamber, leading to a sudden increase in intraocular pressure. The treatment for open-angle glaucoma focuses on reducing the elevated intraocular pressure by either decreasing the secretion of aqueous humor or increasing its outflow.
Drugs such as carbonic anhydrase inhibitors, α2- and...
Drugs such as carbonic anhydrase inhibitors, α2- and...
01:28Angle Closure Glaucoma: Treatment
Angle-closure glaucoma, or closed-angle glaucoma, is an eye condition where the iris bulges out and blocks the iridocorneal angle, resulting in a buildup of aqueous humor and increased intraocular pressure. Immediate medical attention is necessary due to the sudden onset of symptoms. The treatment for angle-closure glaucoma includes short-term and long-term approaches. Short-term treatment involves using eye drops like pilocarpine to lower intraocular pressure by increasing aqueous humor...
01:23Ophthalmic Drug Delivery Systems
Ophthalmic drug delivery faces major limitations due to poor absorption across the corneal membrane. This process is primarily driven by diffusion and is influenced by two main factors: the physicochemical properties of the drug and tear drainage. Most ophthalmic drugs, such as pilocarpine, epinephrine, atropine, and local anesthetics, are weak bases. They are typically formulated at an acidic pH to enhance chemical stability. However, this leads to high ionization, reducing their ability to...