It is a well-known fact that your near vision becomes poor after cataract surgery. This almost always happens when a monofocal intraocular lens (IOL) has been implanted during cataract surgery and, in some cases, where bifocal or multifocal IOL has been implanted. This problem is usually easy to manage and can be rehabilitated by using corrective glasses or contact lenses.
Monofocal IOLs are meant for correcting distance vision. The near vision remains uncorrected and requires glasses after cataract surgery. Bifocal and multifocal IOLs are designed to provide both near and distance vision.
The reason glasses may still be required after implantation of bifocal or multifocal IOL is that the final visual outcome is not 100% predictable with the current technology for IOL power calculation and surgical techniques.
Hence, the postoperative residual refractive error may still be an issue. For example, the postoperative residual refractive error after implantation of a bifocal IOL may be within ±0.5 D of the intended refraction.
An intraocular lens is implanted in the eye immediately after removal of cataract. Intraocular lens is an artificial lens to replace the natural lens which had lost its transparency and thus become a cataract. The purpose of implanting IOL is to help us continue to see well after removal of our natural lens, which had become cataractous.
As mentioned above, intraocular lens (IOL) may be of the following types:
1. Monofocal Intraocular Lens
A monofocal intraocular lens is an artificial lens that corrects only distance vision. After cataract surgery, the person needs glasses for near vision.
2. Bifocal Intraocular Lens
A bifocal intraocular lens is an artificial lens that has two optical powers, one for distance vision and the other for near vision. We can adjust the power of each component in order to provide good vision at distance and near as well.
After surgery, no glasses are usually required for near vision.
3. Multifocal Intraocular Lens
Implantation of multifocal lens has become the standard of care for cataract surgery. They help the person see all objects at all distances. However, multifocal IOLs have been associated with a higher incidence of visual symptoms, such as halos, glare, or starbursts compared to monofocals. For the past decades, various technologies have been developed to attempt to avoid these symptoms.
When multifocal IOL is implanted, glasses for near vision are not needed after surgery.
A bifocal or multifocal IOL (with two or more optical powers) may be more suited for those patients who can tolerate the halos, glare, and starbursts that may occur with the these IOLs.
Why Is My Close Up Vision Worse After Cataract Surgery?
The natural lens in the human eye has the ability to focus on distant as well as near objects. A person with normal vision can change focus from one object to another by changing the shape of the lens. This phenomenon is known as accommodation. The lens is able to do this because of its elasticity. The lens has a hard central core, known as the nucleus, and an outer layer, the cortex, which is much softer and more flexible.
The lens is able to do this because of its elasticity but the implanted artificial monofocal intraocular lens cannot change shape and focus on multiple distances. In fact, the intraocular lens has no elasticity. Therefore, it is unable to focus on distant objects as well as near objects. Thus, after cataract surgery, you will need glasses for near vision.
Therefore, the implantation of an artificial monofocal intraocular lens is not suitable for the patients who do not want to use glasses after cataract surgery.
How Long Does It Take to Adjust to Glasses After Cataract Surgery?
Adjusting to glasses is gradual process that takes place over the first weeks and months.
The first step of adjusting to glasses after cataract surgery is getting used to the visual acuity you acquire after surgery and more so after starting to use corrective glasses for near vision. This may take a few weeks.
After this period, you will notice that your distance vision is clearer than before, but your near vision won’t be as good as it used to be. This means that reading or computer work will require more effort than before.
Wearers of glasses or contact lens users should be aware that they may need to wear them for a few weeks following surgery as their eyes require time to readjust and for their prescription to change.
What Kind of Reading Glasses Do I Need After Cataract Surgery?
In order to determine which type of glasses you need after cataract surgery, you should go through a series of tests. If the surgeon has prescribed reading glasses for you, it is important to find out if they are bifocal or progressive lenses. You will need to know the power and the distance (far, intermediate, near) for which you need your glasses for.
Bifocal lenses are necessary for those who have difficulty focusing on near and far objects. They are incorporated in the same frame so the wearer can adjust between reading text close up or seeing objects at a distance. Progressive lenses are more expensive but offer better vision for more complex tasks.
Bifocal lenses have the property of providing a clear view of the near and far distances while multifocal lenses provide clearer vision at all distances. They are made up of two optical components, one near to see close objects, and one far to see objects in the distance. Multifocal lenses have only one optical component that provides clear vision at all distances.
What if My Two Eyes Have Very Different Prescriptions?
If you have two eyes with very different prescriptions, you may be wondering if it is possible to wear contact lenses.
Yes, it is possible to wear contact lenses even if your two eyes have different prescriptions. It’s important to take the time to properly examine the differences between your two eyes and find out what your combined prescription is. Once you know your combined prescription, look for a contact lens that fits that prescription.
If your two eyes have very different prescriptions (one eye is nearsighted, the other farsighted), this will not affect how well you can see. However, it will affect your depth perception. When you have trouble seeing something close up, it is because you cannot focus on that object clearly.
In the real world, we have binocular vision because each eye sees slightly different parts of the total visual field, and each eye is in a different place. Your brain fuses the two images, and you see a 3D object.
So basically, you will need different lens prescriptions for both eyes.
When Should I Get New Glasses Made?
Many people do not know that they can get glasses made to help improve their vision after cataract surgery. Current research shows that glasses improve the reading of low-contrast text and reduces visual fatigue. If you’re having trouble with reading, writing, or performing other close work, ask your ophthalmologist about glasses following cataract surgery.
You’ll probably want to wait until after one month has passed since your cataract removal procedure before buying new glasses. Since the prescription might not stabilize for some time yet, don’t start using them right away; instead wait until they become more stable before wearing them.
When you use your new lenses with your current prescription, you might find that the lenses are not as clear as you had previously hoped. This is because your eyes are still adapting to the new lens. You might also notice headaches, fatigue, or other symptoms. This is perfectly normal and a normal side effect of wearing new glasses. If you notice any of these symptoms, you should not wear your lenses longer than necessary.
Improvements in vision after cataract surgery may take a little time. Many people experience a decrease in near vision for a few weeks, followed by an improvement in near vision. There are ways to help improve near vision after cataract surgery. The best way to do this is to wear reading glasses while working on close-up tasks. This ensures that the eyes are not strained at all while attempting to read or work on small items.
In conclusion, near vision after cataract surgery is improved by wearing prescription glasses or choosing a bifocal or multifocal IOL before the surgery.