Just as every individual has a unique appearance, every eye has its own unique optical prescription. However, when optical prescriptions are measured conventionally, people with the same optical prescription are prescribed the same glasses and contact lenses. This is because glasses, contact lenses and conventional refractive surgery only correct shortsightedness, longsightedness and astigmatism. There are many other components of our prescription, known as high order aberrations, that make our vision unique. These components account for haloes, starbusts and glare. Using a device called an Aberrometer, your Doctor can measure these subtle components of vision that are not normally corrected. These results are sent to an advanced laser and computer system that tracks eye movements and calculates the correct number of laser pulses and their location in order to correct both low order and high order aberrations. Custom LASIK offers potential improvement over standard LASIK for night vision where glare, starbusts and haloes can reduce the quality of vision.