My brother has a serious eye disease. He is having difficulty with the multiple crosshair scopes on the market. He needs one with only one crosshair in it. Please don't recommend a rifle scope. They are not designed for crossbow shooting. Are there any makers still making a single crosshair scope for crossbows. I've checked all the brand name crossbow co's but they all sell the multiple hair scopes. His issue doesn't fit well with the electronic dot scopes either. His ideal scope would be a 4X, one crosshair type. Any ideas or suggestions?