yasmin182 wrote:1. my Q however is why is it that when i put my eye drops (for dry eyes) in my vision is crystal clear for a few seconds sometimes minutes??? why is this?
The tear film is an important layer of the cornea. It provides the smoothest surface. If the tears are deficient, the relative roughness of the underlying layer will provide degradation in vision. When you put in eye drops you create that smooth tear film layer and the quality of your vision returns to normal. As those drops dissipate, your vision quality is reduced. You apparently have
Lasik induced dry eyes, which is common and commonly temporary.
yasmin182 wrote:2. is it possible to detect regression this early? my optometrist has said that i will need an enhancement and with regards to enhancements-
Regression is when the refractive error after Lasik or similar laser eye surgery moves back toward its original amount. It is detectable the moment it occurs.
yasmin182 wrote:3. what is the minimum thickness you need in order to progress with an enhancement? i know that 250 microns needs to be left but how much needs to be there before you can begin and how much on average is lost?
The amount of tissue that will be removed (ablation) for primary or enhancement surgery can be reliably predicted within a pretty good margin of error. It is based upon the amount of refractive error correction desired.
Calculations for flap thickness, ablation depth, and corneal thickness can determine how much residual cornea remains after surgery. The thickness of the untouched cornea can be measured intra-operatively immediately after the flap is lifted to affirm that preoperative calculations are correct.
yasmin182 wrote:4. if there isn't enough corneal tissue, is it possible for LASEK to be done instead of LASIK for an enhancement.
Many patients are able to have PRK or LASEK on the Lasik flap, however your individual circumstances would need to be evaluated to determine if this is the most appropriate technique for enhancement surgery.
yasmin182 wrote:5.and i'm not sure if this seems weird, but my eyesight seems clearer outdoors during the day, is this normal?
Absolutely normal at this point in recovery, but not normal later.
When in bright light your pupil size diminishes. The light that reaches inside the eye and is "seen" travels through a smaller area of the cornea and lens. Since all corneas and lenses have irregularities, the smaller the surface through which the light passes, the less the irregularities degrade vision.
The human eye is like a camera in that when the iris is constricted and the pupil is small, there is a greater range of focus. Items close as well as items distant are in focus.
The outermost edge of the cornea is where the edge of the flap is located, and this edge can cause irregularities until healed. When the pupil is large you have a greater surface of irregularities through which the light passes, and are more likely to have a negative effect from both the flap edge and the edge of the laser treatment zone.
It is common for vision to be better in bright light (small pupils) than in low light (large pupils) during the normal six month healing period. If this issue is problematic and does not resolve with healing, discuss with your doctor the exact nature of the problem and how it may be resolved.