One of the most common age-related eye conditions that affects millions of people worldwide is cataract, which is characterised by the opacification of the natural lens of the eyes.
Cataracts can occur in one or both eyes. Most people start developing cataracts after 40 years of age, but symptoms are typically seen after 50.
While various surgical and non-surgical treatment options are available for cataracts based on the severity of the condition, the majority of patients require surgical intervention to manage the symptoms. The intent of this content piece is to help you understand the different types of lenses and the factors that govern the selection of them.
Types of Lenses
1. Monofocal Intraocular Lenses
The monofocal intraocular lenses are the most commonly implanted lenses during cataract surgery. They have a fixed focal length. They help provide clear vision for a particular distance. Monofocal lenses bend light to focus on a specific set distance, usually far, after implantation.
Monofocal lenses offer several advantages, including affordability and high clarity of image at the chosen focal point. However, people with monofocal lenses may require glasses for near or intermediate vision.
Monofocal lenses are the standard lenses which fit perfectly for budget-conscious patients or retired individuals and are usually covered by government schemes, such as Ayushmann Bharat or medical insurance.
2. Multifocal Intraocular Lenses
Premium lenses that help patients achieve optimal vision at multiple distances are known as multifocal intraocular lenses. These lenses have multiple concentric rings with different focal points, which help direct incoming light to different distances simultaneously.
This allows the brain to gradually learn to choose the correct focus depending on the task. With multifocal intraocular lenses, bifocals or progressive lenses are not needed, which is a significant advantage for patients.
They are a wonderful option for people looking for clarity in reading, driving, or usage of digital devices. However, visual disturbances such as halos and glare may be present.
Additionally, a specific issue known as neuroadaptation can arise with multifocal lenses, meaning the brain may take time to adjust to how the lens works. The cost of multifocal lenses depends on the reputation of the hospital along with the expertise of the surgeons.
3. Toric Intraocular Lenses
Toric intraocular lenses are the specialized lens for patients struggling with astigmatism. In astigmatism, the front surface of the eye or the lens inside the eye is curved differently in one direction than the other, affecting normal vision.
Toric lenses help correct the irregularity of the corneal shape, which causes blurry vision. They can be used for patients struggling with cataract and astigmatism, helping sharpen the overall quality and clarity of the image.
Toric lenses are usually expensive compared to standard monofocal lenses, but they are ideal for anyone with significant cylindrical power in cases of astigmatism. For mild astigmatism, low cylindrical toric lenses are available.
For moderate to high astigmatism, high cylinder toric lenses are used. On the other hand, custom toric intraocular lenses may be used for personalised treatment in cases of irregular corneas.
4. Extended depth of focus (EDOF) lenses
Extended depth of focus (EDOF) lenses are an evolution of multifocal lenses and are designed to offer a continuous range of vision. They extend the focus range by stretching the focal point and reducing the jump between distances.
This helps improve visual clarity and reduce side effects such as glare or halos, which usually occur with multifocal lenses. However, for near vision, patients may still require reading glasses.
5. Light Adjustable Intraocular Lenses
The only intraocular lenses that can be adjusted after surgery are the light adjustable lenses. These lenses remain adjustable after implantation. Special light treatments help alter the lenses to optimise focus and achieve perfect vision.
This is a wonderful option for patients with previous eye surgeries, such as LASIK. However, these lenses require regular follow-up visits with the ophthalmologist and necessitate wearing UV-protective glasses until treatment is finalised.
6. Accommodating Intraocular Lenses
Accommodating intraocular lenses are special lenses designed to move within the eye to reduce the effort of eye muscles. They shift backward and forward inside the eye using the eye's ciliary muscles to adjust focus at different distances.
They help mimic the natural function of the eye and offer better immediate vision correction compared to monofocal lenses. Additionally, they have fewer side effects compared to multifocal lenses.
Factors that Determine the Type of Lens
There are several factors that govern the selection of lenses for cataract surgery. Some of the factors are listed below:
- The lifestyle of the patient primarily governs the selection of lenses. People whose work requires frequent use of computers or laptops, or those who drive at night, require specific kinds of lenses.
- The visual goals of the patient also help determine the best type of lens for cataract surgery. For people wanting to be free from glasses, specific lenses are available.
- The eye conditions that an individual has, such as astigmatism or glaucoma, require specialised lenses as per them.
- In addition to it, budget, government schemes, and medical insurance coverage also play a role in determining the lens a patient may choose.
Explore more on cataract surgery and cataract treatments.
Why Lifestyle Matters When Choosing a Cataract Lens?
While the medical aspect of removing the cloudy lens and restoring clear vision is important in cataract surgery, it is equally important to select the type of lens, as it will ensure the day-to-day comfort of the person.
There are several lifestyle and visual goals which must be adequately discussed with healthcare providers or doctors before the operation to select the best lens suitable to your condition.
- Different Visual Needs: It is essential to understand that every individual has different visual needs based on age and the work they are engaged in. While monofocal lenses give clear vision at a certain distance only, people with astigmatism need to opt for toric lenses instead of monofocal lenses due to cylindrical power. In addition to this, to see clearly at multiple distances, multifocal and trifocal lenses are recommended.
- The Type of Work One Is Engaged In: People spending more than 8 to 10 hours on laptops or digital devices require multifocal or extended depth of focus lenses, as they provide better flexibility. Apart from this, for people who rarely use digital devices and are engaged in day-to-day activities such as gardening or visiting temples, a monofocal lens would suffice. For teachers and students, multifocal or extended depth of focus lenses are the best suited. On the other hand, for photographers or designers who require crisp vision across all distances and lighting, trifocal lenses are recommended.
- Driving Habits: It is also essential to note that driving habits govern the selection of lenses as well. If a patient drives often after sunset or in dim lighting, monofocal or extended depth of focus lenses are preferred in such cases. Therefore, commute patterns and travel habits also influence the selection of the lenses.
- Budget Considerations: While premium lenses are available that can cost up to ₹1 to ₹1.5 lakhs per eye, if the lifestyle of an individual does not require them, there is no point in investing such a sum. Apart from this, several government schemes and medical insurance plans are also available that cover the costs of cataract lenses.
Lens selection is best guided by a best cataract surgeon in Mumbai.
FAQs
Which lens is best for cataract surgery in India?
The best cataract lens depends on your lifestyle and visual goals. For instance, monofocal lenses are budget-friendly. However, people with astigmatism require toric lenses.
Can cataract surgery correct astigmatism?
Yes. Astigmatism can be corrected during cataract surgery by the use of toric lenses, which help in correcting the irregularity of the corneal shape.
Are premium lenses worth it?
The decision depends on your lifestyle and visual goals. If one is seeking freedom from glasses and has the ability to invest, premium lenses are worth considering as they reduce post-operative hassle.
Is cataract lens surgery covered under insurance in India?
Yes, many insurance policies and government schemes such as Ayushman Bharat cover monofocal lenses and partial costs of premium lenses. It is recommended to consult municipal corporations of your city and your healthcare provider for detailed information.
Get expert guidance on lens choices, surgery planning and the approach suited to your vision needs.
