What causes light lines after cataract surgery? (+3 reasons)

In this article, we will discuss the reasons that make you see diagonal light lines after a cataract surgery. We will also discuss your lifestyle choices that may increase the incidence of seeing light lines after cataract surgery.

What causes light lines after cataract surgery?

The following table describes the reasons causing light lines after cataract surgery (1):

Characteristic of light line Reason
Glare High refractive index of intraocular lens (IOL).
Starbursts and light streaks Backscattering from the IOL combined with microsaccades.
Light arcs Perception of the edge of IOL at night by the patient.
Haloes and rings Caused by multifocal IOLs that produce hales around the natural or artificial light.
Light flashes Peripheral light ray reflection from the IOL’s edge.

Post-cataract surgery, about 67% of the patients experience positive dysphotopsia. However, it usually disappears within a few weeks. Only 2.2% of the patients have reported persistent positive dysphotopsia up to 1 year after cataract surgery (1).

What postoperative factors cause light lines after cataract surgery?

The postoperative factors, selection of the lens and IOL design might cause light lines after cataract surgery. 

  • Refractive error: Refractive surprise, that is the deviation from the targeted angle, can cause light lines after cataract surgery.

If the incidence angle of light rays onto the IOL exceeds 35° off the visual axis, it might cause an internal reflection that can project onto the temporal retina as a light line (3).

  • Intraocular lens selection: In the case of diffractive multifocal IOL, slight tilting may cause positive dysphotopsia and light line formation.

According to one of the clinical trial data, the ovoid-shaped IOL caused light lines in the majority of the patients (n=289) (4).

  • IOL design: Sharp-edge IOLs increase the chances of seeing haloes as compared to square-shaped IOLs and round-edge IOLs (5).
  • IOL scratches: Damaged and scratched IOL can cause light lines, blurred vision, and impaired night vision. In this case, the damaged IOL should be immediately removed (6).
  • Posterior capsule opacification: It is a postoperative complication of cataract surgery and occurs due to the cloudiness of the lens capsule over time.
  • Pupil size: A larger and wider pupil often exposes the IOL’s edges to more light rays. This causes arc-light patterns and glare due to internal reflections (5).

Which other factors cause light lines after cataract surgery?

After cataract surgery, the patient should not use previous spectacles or contact lenses. The following factors might cause light lines after surgery, including:

  • Spectacles: If the patient requires prescription spectacles following cataract surgery, they will most likely be different from the one the patient was using before the surgery.

Typically, the patient has to wait up to 6 weeks before receiving the prescription spectacles and resuming wearing glasses. After surgery, the patient is also advised to wear protective glasses till healing.

  • Contact lenses: Like spectacles, the prescription of contact lenses will also change after the cataract surgery. Incorrect usage might cause light lines.

The patient needs to wait for one month or several weeks before starting to wear contacts. Consultation with the ophthalmologist should be done before resuming contact lenses.

  • Artificial lashes: They might interfere with the light entering the eye and cause light lines after cataract surgery.

It is advised not to wear artificial lashes for four weeks post-surgery.

How light lines after cataract surgery can be minimized?

Although, an opthalmologist is the best judge in selecting the perfect IOL for cataracts, some of the suggestions to reduce the incidence of light lines after cataract surgery include:

  • Equi-biconvex IOLs: These IOLs cause less internal retinal illumination because they enable inner-reflected rays to fall on the retina in a more dispersed way.
  • Acrylic IOLs: These IOLs are more flexible and allow minimal light line formation after cataract surgery.
  • Round-edge IOLs: These designs can reduce the incidence of positive dysphotopsia.
  • Diameter: IOLs with 7 mm diameter are known to cause less incidence of light line formation (7).

As a pharmacist in the optic section, most of the patients complain of light lines and blurred vision after cataract surgery. There is no pharmacological treatment for it and you must visit your opthalmologist for better clinical interventions.

It is important to note that some drugs might also cause vision problems, such as antidepressant drugs like Lexapro. Therefore, your opthalmologist would be the best judge of your underlying condition. 

The clinical interventions are made on an individual basis and the severity. Sometimes you might need an IOL change, especially if the previous IOL was damaged. The light lines disappear after some time.

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Khoramnia R, Auffarth G, Łabuz G, Pettit G, Suryakumar R. Refractive outcomes after cataract surgery. Diagnostics. 2022 Jan 19;12(2):243. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8870878/


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Bonsemeyer MK, Becker E, Liekfeld A. Dysphotopsia and functional quality of vision after implantation of an intraocular lens with a 7.0 mm optic and plate haptic design. Journal of Cataract & Refractive Surgery. 2022 Jan 1;48(1):75-82. https://www.sciencedirect.com/science/article/abs/pii/S0886335000008567