Watching television for a long time can cause eyestrain. One of the ways to minimize eyestrain is to choose a TV with a higher refresh rate. Refresh rate is how many times per second the picture is updated, or, put in other words, how many times it flickers. The more flickers per second the smoother the picture, which translates to less strain for your eyes.
Another important factor that will affect your eyesight is the light omitting technology that has been used to manufacture your TV screen. There are two main technologies that are currently used in TV screens: light-emitting diode (LED) and organic light-emitting diode (OLED).
Studies show that “LED light induces oxidative stress and stress-response pathways, which result in retinal cell death”; OLEDs, on the other hand, “might be less toxic to eyes than LEDs" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7360575/).
OLED screens are considerably more expensive than their LED counterparts, but they are likely to cause less damage to your eyes. Combined with the superb picture quality that the OLED TV delivers, it might be worth to invest in one.