Seeing Halos Around Lights
Halos around lights are bright rings or circles around different light sources such as headlight. Another forms of vision problem similar to that is starburst around lights.
Starbursts around lights are fine radiating filaments from lights. Both of these vision problems can occur at ant day time but mainly at night and also both of them have the same causes.
The reason behind this vision problem is abnormal refraction of lights that enter the eye and instead of these lights to be focused on the retina, they scattered away.
Halos around lights due to Fuchs Corneal dystrophy appears at the morning and gets better throughout the day gradually and the reason behind that is corneal edema is more in the morning and the cornea becomes little bit dehydrated throughout the day.
Causes of Seeing Halos around Lights
Halos around lights are caused by abnormal reflection of lights that enter the eye.
There are many causes of that and here are the most common causes:
1- Eyeglasses and contact lenses
Scratched and damaged lenses of the eyeglasses can cause that. Lenses that are not coated with antiglare can also cause that especially at night.
Wearing contact lenses for long hours makes the contact lenses dry and also makes your eye dry. Sometimes wearing them for long hours can cause corneal edema or swelling of the cornea in which you will start to see rainbow halos around light.
2- Corneal Causes
One of the most common causes is dry eye syndrome.
Other common causes are:
1- High astigmatism. People with high astigmatism usually complain of this problem. Corneal ectasia and keratoconus are examples of corneal diseases that cause high astigmatism.
2- Keratoconus. People with keratoconus can also see this vision problem due to:
- High astigmatism.
- Corneal edema. One of the complications of keratoconus is acute corneal hydrops in which there is rupture of the inner layers of the cornea with corneal edema.
- Corneal scar. Corneal scar can be caused by healed corneal hydrops.
- Early post operative period of keratoconus treatments such as corneal cross linking, corneal rings and corneal graft.
3- Corneal abrasion. Any defects on the external layer of the cornea can also cause this vision problems. Corneal abrasion can be cause by eye trauma, severe dry eyes and wearing contact lenses for long time.
4- Corneal edema and corneal scar.
There are many diseases that can cause corneal edema and scar such as corneal infection, corneal ulcer, fuchs dystrophy, high intraocular pressure, keratoconus and herpes eye infection.
5- Early post-operative period of Corneal procedures and surgeries such as refractive eye surgery, corneal graft, corneal cross linking, corneal inlays and so on. In the early post-operative period, there is corneal edema from the surgery itself and after few days, the corneal edema disappear and vision return to normal without seeing halos around lights.
3- Cataract
Cataract is cloudy of the natural crystalline lens inside the eye. People with cataract can see halos around the light especially at night.
4- Cataract Surgery
Cataract surgery can cause halos around lights by:
- From the surgery itself that can cause temporary corneal edema from high intraocular pressure, long surgery and intraocular inflammation.
- Formation of posterior capsular opacity which usually appears 2-3 month after the cataract surgery and it can be treated with YAG laser capsulotomy.
- Multifocal intraocular lens implantation. People with multifocal intraocular lens usually complain of halos around lights especially at night more than people with monovision intraocular lens implant.
5- Glaucoma
Sudden increase of intraocular pressure can cause corneal edema and rainbow halos around lights with headache, red eye, ocular pain and blurry vision. This is a medical emergency and should be treated as soon as pssoible to prevent any permanent vision loss.
The most common types of glaucoma that can cause sudden increase in intraocular pressure are primary closed angle glaucoma and phacomorphic glaucoma.
6- Ocular migraine
People with ocular migraine usually complain of headache with visual problems such as halos around lights.
When to seek urgent medical care
Sudden appearance of halos around lights with red eye, eye pain or blurry vision require urgent care as it might be caused by high intraocular pressure which should be treated as soon as possible to prevent permanent loss of vision.
