Eyesight changes completely

Thank you for your question on ehealthforum.com

Let me initially assure you that you do not have anything abnormal going on with your vision or eyes. What you are describing is completely normal. It happens in darkness in most of the people. You are observant enough to observe it. In near or total darkness, our vision accommodative muscles in the eye contract to focus more vigorously than in light conditions. This accommodation process goes into continuous mode when there is not light source to focus on, this process will give you a feeling of visual field changes. In fact, a normal person's vision is not the same in near or total darkness due to this process. A normal seeing person with 20/20 vision becomes slightly myopic and it is called ' Night or accommodative Myopia' which is more noticeable when you are driving on motor/highway on a dark night. Night myopia may be up to -0.75 D in emmetropic (no sight) people. Hope this information keeps your mind at rest and is helpful. Thank you.