Stars don't emit a narrow band frequency of light
Stars are not lasers. Stars emit energy based on their surface temperature, in rough accordance with expected blackbody emissions from an object of that temperature. You can see on the graph above the emission magnitude (in log scale on the y-axis) for different wavelengths (x-axis). These wavelengths are a small pieces of the overall spectrum, but you can see how all stars emit at all frequencies.
Also note that the white and blue giant stars (in the 10000 K temperature range) emit more light at all wavelengths, often by orders of magnitude, than cooler F and G stars like our sun (with its surface temp of 5777 K).
In your example, a 'UV' star would in the 10000 K range, with lots of emitted energy in the 'UV' range as you can see on the graph. An 'IR' star would be cool M-type red dwarf like the 3000 K line, where peak radiance is in the IR range.
The important thing to note, is that if a planet received radiation from both stars, there would still be a great deal of visible light that the planet received. Both visible spectrum 'eyes' and photosynthesis would be viable on such a planet.
Its also important to note that the graph is on a log scale. There is no IR peak in combined magnitude; the hotter 10000 K star will be so much more powerful as to overwhelm the lesser star. There is no reason to specifically develop sensors for IR, since there will be more energy in the visible spectrum, and even more still in UV.
Overall, despite having two stars with different spectral peaks outside the visible range, you can still use the standard visible light range on your planet.
