使用JS，是否有某种方法可以检测到浏览器窗口中可见的文本？

是的，您需要测量视口以计算距元素顶部的距离。看到这个小提琴。

$.fn.is_on_screen = function(){

    var win = $(window);

    var viewport = {
        top : win.scrollTop(),
        left : win.scrollLeft()
    };
    viewport.right = viewport.left + win.width();
    viewport.bottom = viewport.top + win.height();

    var bounds = this.offset();
    bounds.right = bounds.left + this.outerWidth();
    bounds.bottom = bounds.top + this.outerHeight();

    return (!(viewport.right < bounds.left || viewport.left > bounds.right || viewport.bottom < bounds.top || viewport.top > bounds.bottom));

};

if( $('.target').length > 0 ) { // if target element exists in DOM
    if( $('.target').is_on_screen() ) { // if target element is visible on screen after DOM loaded
        $('.log').html('<div class="alert alert-success">target element is visible on screen</div>'); // log info       
    } else {
        $('.log').html('<div class="alert">target element is not visible on screen</div>'); // log info
    }
}
$(window).scroll(function(){ // bind window scroll event
    if( $('.target').length > 0 ) { // if target element exists in DOM
        if( $('.target').is_on_screen() ) { // if target element is visible on screen after DOM loaded
            $('.log').html('<div class="alert alert-success">target element is visible on screen</div>'); // log info
        } else {
            $('.log').html('<div class="alert">target element is not visible on screen</div>'); // log info
        }
    }
});

的HTML

<div class="log">log</div>

scroll to target element<br> scroll to target element<br> scroll to target element<br> scroll to target element<br>
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scroll to target element<br> scroll to target element<br> scroll to target element<br> scroll to target element<br>
scroll to target element<br> scroll to target element<br> scroll to target element<br> scroll to target element<br>
scroll to target element<br> scroll to target element<br> scroll to target element<br> scroll to target element<br>
scroll to target element<br> scroll to target element<br> scroll to target element<br> scroll to target element<br>
scroll to target element<br> scroll to target element<br> scroll to target element<br> scroll to target element<br>
scroll to target element<br> scroll to target element<br> scroll to target element<br> scroll to target element<br>
scroll to target element<br> scroll to target element<br> scroll to target element<br> scroll to target element<br>
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scroll to target element<br> scroll to target element<br> scroll to target element<br> scroll to target element<br>
scroll to target element<br> scroll to target element<br> scroll to target element<br> scroll to target element<br>


<div class="target label label-info">target element</div>


scroll to target element<br> scroll to target element<br> scroll to target element<br> scroll to target element<br>
scroll to target element<br> scroll to target element<br> scroll to target element<br> scroll to target element<br>
scroll to target element<br> scroll to target element<br> scroll to target element<br> scroll to target element<br>
scroll to target element<br> scroll to target element<br> scroll to target element<br> scroll to target element<br>
scroll to target element<br> scroll to target element<br> scroll to target element<br> scroll to target element<br>

的CSS

.log {
    position: fixed;
    right: 20px;
    top: 20px;
}