Seeing colored halos or rings around lights, often described as “rainbow vision,” can be a disorienting experience. It can appear suddenly or gradually, and while sometimes benign, it may signal an underlying eye condition. Understanding its causes is the first step toward addressing them.
Understanding Rainbow Vision and Its Causes
Rainbow vision occurs when light entering the eye is diffracted, spreading into its component colors, similar to how a prism works. This diffraction happens when there is swelling or cloudiness within the eye’s clear structures, such as the cornea or lens, scattering light and leading to the perception of halos.
One serious cause of rainbow vision is acute angle-closure glaucoma, a medical emergency characterized by a sudden increase in intraocular pressure. This rapid pressure buildup pushes fluid into the cornea, causing edema and light diffraction. Symptoms include severe eye pain, headache, nausea, and blurred vision, requiring immediate medical intervention to prevent vision loss.
Corneal edema can also lead to rainbow halos. Overwearing contact lenses can deprive the cornea of oxygen, causing it to swell and leading to temporary halos. Genetic conditions like Fuch’s dystrophy, which affects the inner layer of the cornea, can cause chronic swelling and morning halos that may improve throughout the day.
The natural aging process can also contribute to this visual effect. Cataracts, a clouding of the eye’s natural lens, can scatter light and create halos or glare, particularly around bright lights at night. Temporary causes include post-surgical effects, such as after LASIK surgery where corneal swelling during healing can cause halos, or certain eye drops that alter pupil size or corneal hydration.
When to Consult a Doctor
Experiencing rainbow vision warrants a professional medical evaluation to determine its cause and treatment. While some instances may be temporary or benign, others indicate serious conditions. Consulting an eye care professional ensures accurate diagnosis and timely management.
Specific accompanying symptoms serve as red flags and require immediate medical attention. If rainbow halos appear suddenly, especially if combined with severe eye pain, a throbbing headache, nausea, or vomiting, it could indicate acute angle-closure glaucoma. These symptoms suggest a rapid rise in eye pressure, which can quickly damage the optic nerve.
Any significant blurring of vision or persistent halos that do not resolve should prompt an urgent visit to an ophthalmologist. These signs can point to conditions like developing cataracts or more subtle forms of corneal swelling that require assessment. Prompt evaluation is important for preserving vision and preventing complications.
Treatment Approaches
Addressing rainbow vision depends on accurately diagnosing its underlying cause, as there is no single treatment for the symptom. A thorough eye examination by an ophthalmologist is the first step to identify the condition responsible. Once the cause is identified, a targeted treatment plan can be developed.
For acute angle-closure glaucoma, immediate treatment aims to lower intraocular pressure rapidly, which might involve eye drops to reduce fluid production or increase outflow, or oral medications. A laser procedure called laser iridotomy can create a small opening in the iris, allowing fluid to drain more effectively and preventing future attacks. Treating the pressure resolves the corneal edema and the associated halos.
If corneal edema is the cause, treatment might involve managing the underlying issue. For contact lens-related edema, this means proper lens hygiene, reduced wear time, or switching lens types. For conditions like Fuch’s dystrophy, hypertonic saline drops or ointments can help draw fluid out of the cornea, reducing swelling and improving vision. In advanced cases, corneal transplantation may be considered.
When cataracts are responsible for halos and glare, surgical removal of the cloudy lens is the definitive treatment. During cataract surgery, the natural lens is replaced with a clear artificial intraocular lens, which eliminates the light-scattering effects that cause halos. Resolving the primary condition effectively eliminates the symptom of rainbow vision.