Eye strain would cause blurry vision, dryness and redness of eyes. Severe eye strain gives patients headache and pain in shoulders. So to have a bad vision due to eye strain is very possible. Long term of eye strain might accelerate the development of refractive problems, which worsens the vision. We have to sit in front of computer and stare at the monitor all day long, which gives most people eye strain. People tend to reduce blinking 5 times less than normal because of long time staring. Blink more to ensure that there is enough tear film to lubricate our eyes. Take frequent breaks to relax the lens and muscles. Have some mild eye massages to promote the blood flow and increase nourishment to eyes. Don't read with too bright or too dim light.
Yes, if your eyes always tired, It likely cause bad vision to you. Besides, tired eyes may also lead to burning eyes, sore eyes, dry eyes, blurred vision and an uncomfortable sensation of the eyelids. Sometimes, eye tired can also lead to headaches, dizziness and migraines. Even if tired eyes won't cause bad vision, you shall treat it. Just take a regular break and get enough sleep. Hope this can help you.
Studies have shown that when the eyes focus for a long time, muscle tone is reduced, affecting muscle movement regulation area in the cerebral cortex, which will lead to nerve excitability decrease, disorder control of neck and shoulder muscles movement.
Eyes are the most susceptible to fatigue. When the eyes are tired, one may feel pain, sore, light-fear. Suffering long-term tired eyes, one will get bad vision easily. It is very useful to let your eyes have a 10min rest every 45min.