Is there a phrase for "I cast a glance" but as in an accident?

Solution 1:

My first thought was that you might glimpse your watch:

glimpse

VERB

[WITH OBJECT]

1. See or perceive briefly or partially.

   ‘he glimpsed a figure standing in the shade’

(from the Oxford Dictionaries)

But then I felt that wasn't quite right. What you really did was catch sight of your watch:

catch (or get a) sight of

Glimpse for a moment; suddenly notice.

‘when she caught sight of him she smiled’

So in your sentence, it would be:

I caught sight of my watch... shoot! It's 10:30!

An anonymous user (thanks, whoever you are!) noticed that the Oxford Dictionaries' definition of glimpse as a noun offers yet another option via its sample sentence:

glimpse

NOUN

1. A momentary or partial view.

   ‘she caught a glimpse of the ocean’

The anonymous user noted that

_this may arguably imply even less intent than to "catch sight," since the latter can sometimes apply to an object one is specifically seeking.-

So perhaps the best option would be:

I caught a glimpse of my watch... shoot! It's 10:30!

(I'm embarrassed that I didn't put the two together myself!)

Solution 2:

One way to do this would be to take yourself out of the subject position. You can make yourself the passive victim of your watch's attention-getting machinations by using the expression catch someone's eye. From MacMillan Dictionary:

if something catches your eye, you suddenly notice it
There was one painting that caught my eye.

So in your example, you were just minding your own business, not meaning to check the time at all, when suddenly

My watch caught my eye...shoot! It's 10:30!