Common Visual Aberrations Following LASIK
1/3 to 1/2 of patients experience night vision problems
Glare - A phenomenon in which, after light has bounced off an object and into the eye, it is reflected again in the eye, producing an optical aberration. Consider a sheet of paper being illuminated by a lamp. To a normal eye it will be sharp and clear. For the Lasik patient with this side effect, the sheet of paper will now have a thin ring of white fuzziness around the edges, perhaps extending for an inch or two. Now take this disturbing visual effect from that single sheet of paper and expand it by the several hundred objects in a typical room, and you are looking through a thin white cloud. Many ophthalmologists never inquire about their patientsí post-operative glare, and if the patient should mention it, the ophthalmologist will give calming reassurances that it will eventually subside. Instead they focus their diagnostic efforts on simplistic eye chart tests and applaud their patients on how well they can read these charts. They ignore visual complications and instead measure a successful outcome as being able to read the eye chart at the 20/20 level, regardless of the fact that the light bouncing off the eye chart creates a degraded image.
Example of Post-Lasik Daytime Glare.Haloes - Glare-related visual aberrations causing a fuzzy, cloudy light surrounding moderately lit objects at night. A red stoplight, for example, will be surrounded by a large red hazy light. Even more disconcerting, haloes fluctuate in size as the pupils naturally expand and contract ever so slightly.
Post-Lasik Glare of Moon.
Pre-Lasik View of Oncoming Traffic.
Post-Lasik Haloes with Oncoming Traffic.
Post-Lasik Haloes with Traffic Lights.
Starbursts - An optical effect surrounding brightly lit, sharper points of light. The Lasik patient with this symptom will see numerous streaks extending in every direction from a light-emitting object -- like a July 4 firecracker. Whatís worse, the light will not be obscured by other objects that may be closer by. As with the glare and haloes, multiply this effect a hundred times and you get an idea of how an otherwise pleasant walk at night down a city street becomes what has been described as a "visual hell," or how the ability to drive at night becomes impaired.
Post-Lasik Starbursts. The Ability to Drive Safely at Night has been Ruined.
Ghosting - A faint double vision that occurs when looking at objects in dim light. This visual aberration is most pronounced when watching a movie in a cinema or on television -- every object gives a faint "ghosted" image right beside it. The level of ghosting fluctuates with changing levels of light, which occurs constantly and is quite distracting.
Post-Lasik Ghosting of Computer Screen.
Post-Lasik Ghosting of Eyechart. Refractive Surgeons Consider This to be 20/20 Vision.
Post-Lasik View of Moon with Severe Case of Ghosting.
Haze - After the cornea has been ablated by the laser, it begins trying to heal itself. This healing produces microscopic scars that for several weeks produce cloudy vision at all light levels. This symptom generally abates over time but given the unpredictable healing response of each individual, for some the haze is permanent.
Epithelial Ingrowth - In some cases following Lasik, epithelial cells will begin growing at the interface between the cornea and the flap after the flap has been re-laid. If the cells do not stop growing, they will begin to cloud and distort vision. In severe cases, epithelial ingrowth can lead to flap melt in which stroma layer cells in the flap are destroyed, resulting in permanent loss of visual acuity. Epithelial ingrowth requires a flap lift to enable the surgeon to clean out the excess cells, and more days of pain and weeks of haze as the re-laid flap heals.
Corneal Abrasion - Upon cutting the flap with the microkeratome, or lifting the flap, corneal cells can be dislodged, producing temporary blindness until healing takes place and requiring narcotic pain killers to reduce the severe eye pain that results.
Dry Eye Syndrome - Goblet cell disruption and corneal nerve damage decrease tear production, leading to dry eye discomfort and necessitating constant use of eye drops and/or punctum plugs and/or cauterization to occlude the drainage ducts.