Dilation of your eyes entails instilling eye drops which causes the pupils, the black spots which are openings, to enlarge. By enlarging the pupils and using certain instrumentation, the doctor is able to see more of the structures inside of your eyes. This leads to better detection and treatment of diseases which can affect the eyes and lead to blindness. The effects of dilation include light sensitivity, blurred vision at far and near, and may affect your ability to drive. Because of these possible side effects, although rare, it is recommended that you arrange for someone to come along with you to drive you home. It is generally not recommended to return to work or school that day and to limit your activities due to blurred vision and light sensitivity. The effects usually last from four to six hours, but may be longer or shorter depending on the individual response.