Contrast level test

What this test screens for and who it helps

This contrast level test is a quick, at-home screening of your contrast sensitivity—how well you can tell subtle differences between shades of gray and low-contrast detail. Many daily tasks rely on contrast sensitivity, including reading faint text, recognizing faces in dim light, and safe night driving. Reduced contrast sensitivity can be related to normal aging and may also occur with conditions such as cataracts or glaucoma. It can also be affected by dry eyes, glare, or an outdated glasses prescription.

This tool can be useful if you notice that things look washed out, if dim environments make it hard to see, or if night driving feels less comfortable than it used to. It is a screening aid only and does not diagnose any eye condition.

How to take the test correctly

• Use a suitable device: A laptop or desktop monitor is preferred for accuracy. A tablet or phone can work, but smaller screens may make the task harder.
• Set your viewing distance: Sit at about arm’s length from the screen (roughly 20–24 inches). Keep your head level and your posture steady.
• Control the lighting: Choose a room with steady, moderate lighting. Avoid strong sunlight, glare, or reflections on the screen.
• Adjust your screen settings: Turn off auto-brightness if possible and set brightness to a comfortable middle level. Use a standard color mode (avoid vivid/high-contrast modes or blue-light filters during the test). Clean your screen to remove smudges.
• Wear your usual correction: If you wear glasses or contacts for computer work or distance, keep them on. If you use progressive or multifocal glasses, look through the central portion of the lenses.
• Test one eye at a time: Cover your left eye with a clean tissue or your hand without pressing on the eyelid, and test the right eye. Then switch and test the left eye. You can also test with both eyes open afterward.
• Follow the on-screen prompts: You may be asked to identify letters, shapes, or patterns that become fainter step by step. Take your time, try not to squint, and guess only when unsure.
• Take brief breaks if needed: If your eyes feel dry or tired, blink a few times and rest for 10–15 seconds before continuing.

How to read your results

Your result indicates how faint a pattern or letter you could still see. In general:

• Good/typical range: If you can detect most of the lighter (low-contrast) steps, your contrast sensitivity appears to be within a typical range for screen viewing.
• Borderline: If you struggle near the lighter steps but can still identify some low-contrast details, your contrast sensitivity may be borderline. Consider repeating the test under ideal conditions.
• Reduced: If you cannot see many of the lighter shades or low-contrast details, especially if one eye performs noticeably worse, your contrast sensitivity may be reduced.

Keep in mind that fatigue, screen settings, and room lighting can affect performance. Results may also vary by device. If your result seems unusual, repeat the test at a different time or on another screen to confirm.

What to do if your result is poor

Don’t panic—an online screening can be influenced by many factors. However, persistent difficulty seeing faint details, glare, or trouble with night driving is a good reason to book a comprehensive eye exam with an eye doctor (optometrist or ophthalmologist). An in‑person exam can assess your glasses or contact lens prescription and check the health of your eyes.

Practical steps while you wait

• Use steady, brighter task lighting for reading and detailed work.
• Increase on‑screen contrast, enlarge text, and reduce glare where possible.
• Avoid night driving if you do not feel safe seeing road markings or pedestrians.
• Note which eye performed worse and any specific situations that are difficult (for example, dim restaurants or rainy evenings) and share these with your eye doctor.

Seek urgent care if you have a sudden drop in vision, eye pain, flashes of light, a curtain over part of your vision, or other acute symptoms.

Limitations of online tests

• Device variability: Screen size, brightness, color balance, and viewing angle can change how faint details appear.
• Environmental factors: Room lighting, glare, and eye fatigue can affect your score.
• Not a diagnosis: This screening cannot diagnose cataracts, glaucoma, or any other condition. Only a comprehensive eye exam can evaluate your eye health.
• Not a full measurement: This test does not map your complete contrast sensitivity function or replace clinical charts used by eye care professionals.
• User factors: Reading ability, attention, and familiarity with screens can influence results, especially in children or in people with visual processing differences.

Disclaimer: This contrast level test is a screening aid and does not replace a professional eye examination. For concerns about your vision or eye health, schedule a comprehensive eye exam with a licensed eye care professional.