There are several signs that it may be time for an eye exam. Here are some common ones:

1. Changes in vision: Any changes in your vision, such as blurred or double vision, difficulty seeing at night, or a sudden loss of vision, may indicate a problem with your eyes and warrant an eye exam.

2. Eye discomfort or pain: If you experience eye discomfort, pain, redness, itching, or discharge, it may be a sign of an eye infection or other problem that requires an eye exam.

3. Headaches or eye strain: If you experience frequent headaches, eye strain, or fatigue, it may be a sign that your eyes are overworked and in need of an exam.

4. Family history of eye disease: If you have a family history of eye disease, such as glaucoma, macular degeneration, or cataracts, you may be at higher risk for developing these conditions and should have regular eye exams to detect any early signs.

5. Chronic conditions: Certain chronic conditions such as diabetes, high blood pressure, and autoimmune diseases can increase the risk of eye problems, so it's important to have regular eye exams if you have one of these conditions.

6. Age: As we age, the risk of certain eye diseases such as cataracts, glaucoma, and macular degeneration increases, so regular eye exams become more important.

If you experience any of these signs or symptoms, or if you have concerns about your eye health, it's important to see an eye doctor as soon as possible. Additionally, even if you don't have any symptoms or risk factors, it's still important to have regular eye exams as a preventative measure to detect any potential problems early.