The dark spot floating in your left eye is undoubtedly a floater. This is a small amount of vitreous or retina material that has become dislodged and is floating about in the clear liquids inside the eye.
Floaters are somewhat common as we age and for those who are very myopic (nearsighted, shortsighted). The floaters my have been caused by the Lasik surgery process, but more likely they existed before but were out of your line of sight. Lasik disrupted them and mixed up the fluids in your eye, moving the floater in a new position that is now disruptive.
There really is not much that can be done about most floaters. Ive seen doctors attempt to use lasers, but that can only break a floater into smaller pieces, not remove it or destroy it. Having many small floaters is not necessarily better than one larger floater.
The brain is normally pretty good at learning to "look around" and ignore a floater. This is exactly the same process as your blind spot.
Everyone has a spot in their vision that is fully blind. It is where the optic nerve enters the eye. We all have one, but we really dont "see" it because the brain has learned to simply ignore that area of vision and look around it. If the floater is reasonably stable, the brain will learn to ignore it too. If you focus on the floater or are otherwise floater aware, that will slow the process.
It is possible that the night vision problems you have encountered after Lasik will continue to resolve, but at four months postop most of your healing has completed. We consider the process complete at six months postop.
The exact cause of the halos needs to be determined. In most cases it is because the area at the outer edge of the cornea is not fully corrected, but the central area is fully corrected. For some people, the unfocused light at the edge combines with the focused light and creates a blurred image around the main image. This presents as a halo of light from light sources and would normally present in low light environments when the pupils are large and allow light passing through the undercorrected ring at the edge of the cornea to reach the retina and be "seen". You may want to read about Lasik and Pupil Size issues at http://www.usaeyes.org/lasik/faq/lasik-pupil-size.htm
Correction of the undercorrected edge of the cornea can resolve the problem. In the interim, the eye drop Alphagan P has been shown to reduce the size of the pupil and block the light passing through the undercorrected area of the cornea from reaching the retina. Ask your doctor if this medication would be appropriate.
Only your doctor can tell you if enhancement surgery would be appropriate to resolve your night vision problems. You may find that contact lenses are acceptable. They are worth a try.
Glenn Hagele
http://USAEyes.org
Lasik Patient Advocacy & Surgeon Certification
I am not a doctor.
