To be absolutely certain, you should:
* Check the part numbers: The most reliable way is to find the part number for the windshield on both a 1995 and 1996 Eldorado. If the part numbers match, they are interchangeable. You can usually find this information on the glass itself (often a small sticker in a corner), in a parts catalog (like from a Cadillac dealer or online parts supplier), or by providing your vehicle's VIN to a parts supplier.
* Consult a glass replacement shop: Auto glass shops have databases that cross-reference part numbers and fitment. They can tell you for sure if a 1996 windshield will work on your 1995 model.
Don't rely on just assuming they are the same. The small cost of verifying fitment with a professional far outweighs the cost and inconvenience of getting the wrong part.