Patients with keratoconus experience more scattered light nuisance than people without this eye condition. Stray light has a blinding effect. Sunlight is experienced as extremely bright. This is why patients with keratoconus are quick to reach for sunglasses. In more severe cases, a cap with a sun visor should be worn. In extreme cases, sunlight is avoided and the patient stays indoors. These restrictions may be avoidable.
Stray light behaves differently than the light in healthy eyes. The light is not focused on the yellow spot (the fovea), but also illuminates the entire retina. A pilot study by the Keratoconus Center in the Netherlands shows a significant relationship with the degree of keratoconus and the degree of stray light nuisance.
Patients with keratoconus are dependent on the correction of contact lenses. However, some contact lenses can increase stray light levels. This reinforces this complaint instead of correcting it.
In 2022, the Keratoconus Center in the Netherlands will conduct scientific research into stray light nuisance from different types of contact lenses for patients with keratoconus. It is being investigated whether two new types of wavefront corrected contact lenses cause less stray light nuisance than regular keratoconus contact lenses.
Just as sunlight can be very dazzling, annoying headlights can also cause dangerous situations in traffic. Stray light nuisance can also cause complaints such as fatigue, headaches and watery eyes. The cause of stray light nuisance in keratoconus patients is still unknown, as are the causes of increased stray light nuisance when wearing contact lenses.