Bright daylight can feel like a lot after a knock to the head. Many people notice that the walk to the car, the drive with the sun low in the windshield, or lunch on a patio sits differently than it did before. This article describes a simple way to keep a light log in the days before you see an examiner in the St. Louis area, so the information you bring is concrete instead of a general sense that things feel worse outside.
This is educational information only. A log cannot tell you what is causing a headache, and it does not replace an examination. Its job is to give the person examining you a clear picture of when, where, and for how long.
Why light gets its own column
Most people describe everything as the headache getting bad. Light is worth separating out because it is one of the easier things to describe. You can ask yourself whether you were outdoors, whether you were squinting, whether you wore sunglasses, and whether you had to turn away from a window or a grocery store aisle. Those are observable facts you can write down in under a minute.
Keep this log separate from your screen time and eye movement notes, which are their own topics. Here the focus is the outdoor and indoor brightness you move through during a day.
What to write down each day
Use one short block per day. Start with the date, then add a few fields:
Time outside, in rough hours. For example, about an hour mid-morning, then a short walk at lunch.
Sun level. Note whether it was overcast, bright sun, or low sun in the late afternoon. Low sun coming straight into your eyes on a drive is a different experience from a cloudy day, so write down the direction too if you can.
Eyewear. Write whether you wore sunglasses, a hat with a brim, or nothing. Note if the lenses were the pair you normally use.
Squinting or turning away. Count it roughly. If you shielded your eyes with your hand or looked down to avoid light, write that down.
Where you had to be. A grocery store, a parking garage, a ballfield, or a church parking lot. Place names help more than general words.
Headache description in your own words. Use plain terms such as mild, steady, sharp, or heavy, and note when it started and when it eased, if it did.
Glare on the metro roads
Anyone who drives around the metro knows how quickly light can change on a highway at sunset, or when you crest a rise with the sun directly in your windshield. Afternoon glare can be strong on some westbound routes, especially in the fall when the sun sits lower. If you drive, note the route and the time of day. If someone else drives you, note that too, along with whether you asked them to lower the visor or dim the cabin lights.
Outdoor events are another place to log. A football game, a farmers market, or a long walk along the river can have very different light than an indoor errand. Those differences matter because they help you tell a single bright moment apart from a repeating pattern.
Turning the log into something useful
Before your visit, read the log once and circle any day that stands out. Then write a three-line summary at the top of the page: the typical light you were in, the days that felt harder, and any changes you made, such as adding a hat or leaving a store earlier. Bring the page, or a photo of it, to your appointment.
If you were advised to keep logging after the visit, continue for as long as recommended. A few weeks of plain notes can show whether changes in light exposure seem to line up with how you feel, or whether they do not. That information helps the person making decisions about your care, even if the answer is that light is not the main factor.
When to stop logging and get care
A light log is for everyday observation. It is not a place to wait out symptoms that are getting worse or that come with weakness, confusion, trouble speaking, vision loss, repeated vomiting, or a headache that feels like the worst you have ever had. Those are reasons to seek care right away instead of adding another line to the notebook.